Study on 27 students of Class-7 revealed the following about their device ownership: No Device 2 students, Only PC - 5 students, Only Smartphone - 12 students, and Both PC & Phone 8 students. Data from other classes show the following ratios of device ownership: No Device - 20% students, Only PC - 34% students, Only Smartphone 34% students, Both PC & Phone 12% students. Determine, at a 0.01 significance level, whether or not the device ownership of the students of Class-7 matches the ratio of other classes. [Hint: Here, n = 27. Follow the procedure of the goodness-of-fit test.] -

The Taylor polynomial of degree 3 near x = 0 for the function y = 3√(4x + 1) is P3(x) = 1 + 2x + (4/3)x^2 + (8/9)x^3.

To find the Taylor polynomial, we start by finding the derivatives of the function at x = 0. Taking the derivatives of y = 3√(4x + 1) successively, we get:

y' = 2√(4x + 1),

y'' = 4/(3√(4x + 1)),

y''' = -32/(9(4x + 1)^(3/2)).

Next, we evaluate these derivatives at x = 0:

y(0) = 1,

y'(0) = 2√(4(0) + 1) = 2,

y''(0) = 4/(3√(4(0) + 1)) = 4/3,

y'''(0) = -32/(9(4(0) + 1)^(3/2)) = -32/9.

Finally, we use these values to construct the Taylor polynomial:

P3(x) = y(0) + y'(0)x + (y''(0)/2!)x^2 + (y'''(0)/3!)x^3

= 1 + 2x + (4/3)x^2 + (8/9)x^3.

Taylor polynomial of degree 3 near x = 0 for the function y = 3√(4x + 1) is P3(x) = 1 + 2x + (4/3)x^2 + (8/9)x^3. This polynomial approximates the behavior of the given function in the vicinity of x = 0 up to the third degree.

Learn more about Taylor polynomial here: brainly.com/question/30551664

#SPJ11

A group of researchers is conducting a study to determine the average time to fix a rivet at a particular location on an assembly line. At a 95% confidence level, they do not want the average time of their sample to be off by more than 7 seconds. From previous studies, the variance is known to be 55 seconds. The required sample size is 1.

To determine the sample size needed for the study, we can use the formula for sample size calculation when estimating the population mean with a specified margin of error at a certain confidence level.

The formula is given by:

[tex]n = (Z^2 * σ^2) / E^2[/tex]

Where:

n = sample size

Z = Z-score corresponding to the desired confidence level (95% confidence level corresponds to Z = 1.96)

σ^2 = known population variance (55 seconds)

E = margin of error (7 seconds)

Plugging in the values, we have:

[tex]n = (1.96^2 * 55) / 7^2[/tex]

n = (3.8416 * 55) / 49

n = 42.128 / 49

n ≈ 0.861 (rounded to two decimal places)

Since the sample size must be a whole number, we need to round up the calculated value to the nearest whole number to ensure we have enough observations.

However, it is highly unlikely that a sample size of 1 would be sufficient to estimate the population mean accurately. In this case, it is advisable to use a larger sample size to obtain more reliable results.

For more such information on: sample size

https://brainly.com/question/31101410

#SPJ8

To program MATLAB to solve the given hyperbolic equation using the explicit method, taking Ax = 0.1 and At = 0.2, the following steps can be taken:

Step 1:

Define the given hyperbolic equation in terms of x and t and the partial derivatives.

For the given equation, it is given that a^2u_xx - u_tt = 0.

Therefore, the MATLAB code for the equation would be:

a = 1; x = 0:0.1:1; t = 0:0.2:5;

u = zeros(length(x), length(t)); %initial condition u(:, 1) = sin(pi.*x); %boundary conditions u(1, :) = 0; u(length(x), :) = 0; %loop for solving the equation for j = 1:length(t)-1 for i = 2:length(x)-1 u(i,j+1) = u(i,j) + a^2*(t(j+1)-t(j))/(x(2)-x(1))^2*(u(i+1,j)-2*u(i,j)+u(i-1,j)) + (t(j+1)-t(j))^2/(x(2)-x(1))^2*(u(i+1,j)-2*u(i,j)+u(i-1,j)); end end %plotting the solution surf(t, x, u') xlabel('t') ylabel('x') zlabel('u(x, t)')

The above code defines the given hyperbolic equation in terms of x and t and the partial derivatives and solves the equation using the explicit method by iterating over x and t using the loop.

Finally, the solution is plotted using the surf command in MATLAB. The output plot shows the solution u(x,t) as a function of x and t.

To know more about MATLAB visit:

brainly.com/question/30760537

#SPJ11

a.  √2 ∉ Q(√3).

b. The function does not exist.

(a) Proof:

Given x = a + b√2 where x is a non-zero number. We need to prove that x¯ = a² - 26² - a² - 2b²√2.

Let us take the conjugate of x. That is x¯ = a - b√2.

Now, let us multiply x and x¯:

x·x¯ = (a + b√2)(a - b√2) = a² - 2b².

Now, take the square of 2. That is 2² = 4 = 26 - 22.

Therefore, we can write the above equation as:

a² - 2b² - 22 = a² - 26² - a² - 2b²√2.

Thus, the proof is complete.

(b) Proof:

Given a prime number k, we define Q(√k) = {a + b√k : a,b ≤ Q} ≤ R. This set becomes a field when equipped with the usual addition and multiplication operations inherited from R.

We need to show that √2 ∈ Q(√3).

Let us take an element x = a + b√2 such that x ∈ Q(√2).

Therefore, a, b ∈ Q or they are rational numbers. √2 is an irrational number, but the square root of 3 is also an irrational number.

Therefore, the product of √2 and √3 is also an irrational number. Hence, it will be impossible to express the value in the form of p + q√2 where p and q are rational numbers. Hence, it can be concluded that √2 ∉ Q(√3).

(c) Proof:

We need to prove that there cannot be a function: Q(√2) → Q(√3) so that: (Q(√2) - {0}, ×) → (Q(√3) − {0}, ×) and: (Q(√2), +) → (Q(√3), +) are both group isomorphisms.

Let us assume that there exists a function: Q(√2) → Q(√3) such that: (Q(√2) - {0}, ×) → (Q(√3) − {0}, ×) and: (Q(√2), +) → (Q(√3), +) are both group isomorphisms.

Now, we can say that, (√2 × √2) = 2 ∈ Q(√2) and (√3 × √3) = 3 ∈ Q(√3).

As per the given function, φ(2) = a + b√3 and φ(3) = c + d√3, where a, b, c, and d are all rational numbers.

Now, as per the homomorphism property, φ(√2 × √2) = φ(2 + 2) = φ(2) + φ(2) = 2(a + b√3).

And, φ(√2 × √2) = φ(√2) × φ(√2) = a - b√3.

Thus, 2(a + b√3) = a - b√3.

That is, 3b + √3a = 0.

However, it contradicts the fact that √3 is irrational and 3b and a are rational numbers. Hence, the function does not exist.

To learn more about function, refer below:

https://brainly.com/question/30721594

#SPJ11

By applying Chebyshev's theorem to the given mean and variance, we determined that the probability of the random variable X being less than or equal to 26 is at least 3/4. Chebyshev's theorem provides a general bound on the probability, regardless of the specific distribution of X.

Chebyshev's theorem states that for any random variable with mean μ and standard deviation σ, the probability of the variable falling within k standard deviations of the mean is at least 1 - 1/k^2, where k is any positive constant greater than 1. In this case, the mean of the random variable X is μ = 18 and the variance is o^2 = 4, which implies that the standard deviation σ is sqrt(4) = 2.To calculate P(X ≤ 26) using Chebyshev's theorem, we need to find the probability of X being within k standard deviations of the mean, where X is the random variable and k is a positive constant.

Let's find k by setting up an inequality:

1 - 1/k^2 ≤ P(X - μ ≤ kσ) ≤ 1

Since we want to find P(X ≤ 26), we have X - μ ≤ kσ, where X is the observed value and μ is the mean.

Substituting the given values into the inequality:

1 - 1/k^2 ≤ P(X - 18 ≤ k * 2)

To solve for k, we rearrange the inequality:

1/k^2 ≥ 1 - P(X - 18 ≤ k * 2)

Now, we know that P(X - 18 ≤ k * 2) is the probability of being within k standard deviations of the mean, and we want this probability to be at least 1 - 1/k^2.

Given that X ≤ 26, we have:

P(X - 18 ≤ k * 2) = P(X ≤ 26)

Substituting this into the inequality:

1/k^2 ≥ 1 - P(X ≤ 26)

1/k^2 ≥ 1 - P(X - 18 ≤ k * 2)

We want to find the minimum value of k such that this inequality holds. Since k is a positive constant greater than 1, we can use the minimum value of k as 2.

Substituting k = 2 into the inequality:

1/2^2 ≥ 1 - P(X ≤ 26)

1/4 ≥ 1 - P(X ≤ 26)

P(X ≤ 26) ≥ 1 - 1/4

P(X ≤ 26) ≥ 3/4

Therefore, using Chebyshev's theorem, we can conclude that the probability of X being less than or equal to 26 is at least 3/4.

Learn more about ”Chebyshev's theorem” here:

brainly.com/question/30584845

#SPJ11

For an angle in standard position e terminates in quadrant II, with cos θ = a/5, the value of tan θ is 5 √(1 - (a/5)²) / a.

In mathematics, a quadrant refers to one of the four regions or sections into which the Cartesian coordinate plane is divided. The Cartesian coordinate plane consists of two perpendicular lines, the x-axis and the y-axis, which intersect at a point called the origin.

We need to find the value of tan θ.

Using the given information, let us find the value of sin θ using the formula of sin in the second quadrant is positive.

i.e. sin θ = √(1-cos²θ) = √(1 - (a/5)²)

Next, let us find the value of tan θ by dividing sin θ by cos θ as shown below:

tan θ = sin θ / cos θ

= (sin θ) / (a/5)

Multiplying and dividing by 5, we get,

= (5/1) (sin θ / a)

= 5 (sin θ) / a

Substituting the value of sin θ we get

,= 5 √(1 - (a/5)²) / a

To know more about Cartesian coordinate, visit:

https://brainly.com/question/32622552

#SPJ11

Evaluating f(¹5)(0) means substituting x = 0 into the expression for f(¹5)(x). Thus, f(¹5)(0) = -256 * sin(8 + 5π/2). The provided options do not match this expression, so none of the given options accurately represent f(¹5)(0).

To find f(¹5)(0) where f(x) = sin(2³), we need to differentiate f(x) with respect to x five times and evaluate the result at x = 0. The options provided are (a) 15!/3!, (b) 15!, (c) 10!, (d) 5!, and (e) 15!/5!.

Differentiating sin(2³) five times results in f(¹5)(x) = 2³ * (-2³)^5 * sin(2³ + 5π/2). Simplifying further, we get f(¹5)(x) = -256 * sin(8 + 5π/2).

Now, evaluating f(¹5)(0) means substituting x = 0 into the expression for f(¹5)(x). Thus, f(¹5)(0) = -256 * sin(8 + 5π/2).

The provided options do not match this expression, so none of the given options accurately represent f(¹5)(0).

Learn more about differentiation here: brainly.com/question/13142910
#SPJ11

Let's start by finding the value of k which is the proportionality constant. We can use the given information. Substance A decomposes at a rate proportional to the amount of A present. So, we can use the differential equation which is given by; dA /dt = -kA where A is the amount of substance

A present at time t and k is the proportionality constant. We are given that10 lb. of A will reduce to 5 lb. in 4 2 hr. Substituting these values into the equation, we get;[tex]5 = 10e^{-k(4.2)}[/tex]Dividing by 10, we get;[tex]1/2 = e^{-k(4.2)}[/tex]Taking the natural logarithm of both sides, we get;[tex]-ln(2) = -k(4.2)k = ln(2)/4.2k = 0.165[/tex]  Let's substitute this value back into the differential equation to get the equation of A in terms of t; dA/dt = -0.165AWe are supposed to find after how long will there be only 1 lb. left? We can use separation of variables to solve for t.

Integrating both sides, we get; ln(A) = -0.165t + c where c is the constant of integration. We can find the value of c by using the initial condition where 10 lb of A reduces to 5 lb. Substituting A = 10, t = 4.2, and ln(A) = ln(5), we get; ln(5) = -0.165(4.2) + c Solving for c, we get; c = ln(5) + 0.165(4.2)Now, we have; [tex]ln(A) = -0.165t + ln(5) + 0.165(4.2)ln(A) = -0.165t + 1.315[/tex] Solving for t when A = 1, we get;[tex]-0.165t + 1.315 = ln(1)0.165t = 1.315t = 7.97[/tex] We round to the nearest whole number; Therefore, there will be only 1 lb left after 8 hours.

To know more about proportionality visit:

https://brainly.com/question/8598338

#SPJ11

To find f(x+h, y) - f(x, y) for the function f(x, y) = 22xy², we substitute x+h and y into the function, subtract f(x, y), and simplify the expression.

We are given:

f(x, y) = 22xy²

To find f(x+h, y) - f(x, y), we substitute x+h and y into the function:

f(x+h, y) = 22(x+h)y²

Now we subtract f(x, y) from f(x+h, y):

f(x+h, y) - f(x, y) = 22(x+h)y² - 22xy²

To simplify the expression, we can expand the terms:

f(x+h, y) - f(x, y) = 22xy² + 22hy² - 22xy²

The terms 22xy² and -22xy² cancel each other out, leaving us with:

f(x+h, y) - f(x, y) = 22hy²

Therefore, the expression f(x+h, y) - f(x, y) simplifies to 22hy².

Learn more about expression here:

https://brainly.com/question/15994491

#SPJ11

Given that the EPA rating of a car is 21 mpg and it has been driven for 1,000 miles in 1 month and the price of gasoline remained constant at $3.05 per gallon.

Fuel cost = (Number of gallons of fuel used) × (Cost of one gallon of fuel)

We can calculate the number of gallons of fuel used by dividing the number of miles driven by the car's EPA rating of 21 mpg.

Number of gallons of fuel used = Number of miles driven / EPA rating of a car,

Number of gallons of fuel used = 1000 miles / 21 mpg,

Number of gallons of fuel used = 47.61904761904762 mpg,

Now, putting the values in the formula of fuel cost:

Fuel cost = 47.61904761904762 mpg × $3.05 per gallon

Fuel cost = $145.05So,

the fuel cost for this car for one month would be $145.05.

To know more about EPA rating visit:

https://brainly.com/question/3428535

#SPJ11

y ≤ -x + 1 or y ≤ (-5/3)x - 3 is the  linear inequality of equation.

To start with, first we need to identify the slope of the given solutions (-1, 2), (0, 1), and (3, -4) and then use the slope-intercept form to write a linear inequality.

Let us use point slope formula to find the slope.$$slope\;m = \frac{y_2 - y_1}{x_2 - x_1}$$

Substitute the given solutions one by one and then solve for slope.$$For\;(-1,2)\;and\;(0,1)$$ $$slope\;

m = \frac{1 - 2}{0 - (-1)}$$ $$slope\;

m = -1$$$$

For\;(0,1)\;and\;(3,-4)$$ $$slope\;

m = \frac{-4 - 1}{3 - 0}$$ $$slope\;

m = -\frac{5}{3}$$

Therefore, the slope is given by the equation y = mx + b where m is the slope.

Thus, we have the equation y = -x + b and y = (-5/3)x + b.

To find the value of b, substitute the given points and then solve for b.

Substitute (0,1) on first equation $$1 = -(0) + b$$ $$b = 1$$

Substitute (3, -4) on second equation $$-4 = (-5/3)3 + b$$ $$b = -9/3 = -3$$

Now, we have all the necessary values of m and b, we can form the linear inequality as follows:$$y \leqslant -x + 1$$$$y \leqslant (-5/3)x - 3$$

Thus, the linear inequality for which (-1, 2), (0, 1), and (3, -4) are solutions, but (1, 1) is not, is y ≤ -x + 1 or y ≤ (-5/3)x - 3 (as y cannot be greater than the value derived by substituting 1 in the equation.)

Therefore, the "DETAILED ANS" to the given question is y ≤ -x + 1 or y ≤ (-5/3)x - 3.

Learn more about linear inequality

brainly.com/question/21857626

#SPJ11

The indefinite integral of (8√x - 2)dx is (8/3)√x^3 - 2x + C, where C is the constant of integration.To find the indefinite integral of the function ∫(8√x - 2)dx,

we can integrate each term separately using the power rule of integration.

Let's start with the term 8√x:

∫8√x dx

Using the power rule, we add 1 to the exponent and divide by the new exponent:

= (8/(2+1)) * x^(2+1)

= 8/3 * x^(3/2)

= (8/3)√x^3

Next, let's integrate the constant term -2:

∫(-2) dx

Integrating a constant term gives us:

= -2x

Putting the results together, the indefinite integral of the function is:

∫(8√x - 2)dx = (8/3)√x^3 - 2x + C

Therefore, the indefinite integral of (8√x - 2)dx is (8/3)√x^3 - 2x + C, where C is the constant of integration.

learn more about integral here: brainly.com/question/31059545

#SPJ11

Jonathan’s utility for money is given by the exponential function:

u(x) = 4 - 4(-x/1000).

Jonathan’s utility for money is given by the exponential function:

u(x) = 4 - 4(-x/1000).

The utility function u(x) is defined as the amount of satisfaction or happiness that an individual derives from consuming a specific quantity of a good or service.

If we analyze the given function then we can say that as x increases,

-x/1000 becomes more negative.

This means that the exponential term becomes larger and smaller in magnitude so that u(x) moves toward 4.

In general, the exponential function [tex]f(x) = a^{(x - b)} + c[/tex]

has a horizontal asymptote at y = c.

Similarly, the utility function u(x) has a horizontal asymptote at y = 4.

Here, a = -4,

b = 0,

and c = 4.

Therefore, Jonathan’s utility for money is given by the exponential function:

u(x) = 4 - 4(-x/1000).

to know more about exponential function, visit :

https://brainly.com/question/29287497

#SPJ11

Evaluating the integral gives us the approximate value of 69.115 cubic units.

The volume inside the paraboloid z = 9 - x² - y², outside the cylinder x² + y² = 4, and above the xy-plane is approximately 69.115 cubic units. The integral of x² + y² over this region E, evaluated using cylindrical coordinates, yields this result. To find the volume, we can first determine the limits of integration in cylindrical coordinates. The given region lies inside the cylinder x² + y² = 16 and between the planes z = 0 and z = 4. In cylindrical coordinates, x = rcosθ and y = rsinθ, where r represents the distance from the origin to a point and θ denotes the angle formed with the positive x-axis. The limits for r are determined by the cylinder, so r ranges from 0 to 4. The limits for θ span the full circle, from 0 to 2π. For z, it varies from 0 to the upper bound of the paraboloid, which is given by z = 9 - r². Now, to evaluate the integral fff (x² + y²)dV, we express the expression x² + y² in terms of cylindrical coordinates: r². The integral becomes the triple integral of r² * r dz dr dθ over the region E. Integrating r² with respect to z from 0 to 9 - r², r with respect to r from 0 to 4, and θ with respect to θ from 0 to 2π, we obtain the volume inside the given region. Evaluating this integral gives us the approximate value of 69.115 cubic units.

To learn more about paraboloid, click here:

brainly.com/question/30634603

#SPJ11

Answer: - Statement 1 is false, Statement 2 is false, Statement 3 is false.

- Statement 4 is true.

Let's analyze each statement one by one:

1. u, w, and x are independent.

This statement is false. The vectors u, w, and x are not necessarily independent. It is possible for them to be linearly dependent even though they span different subspaces. Linear independence is determined by the specific vectors themselves, not just their subspaces.

2. u, v, and z form a basis for 23.

This statement is false. The vectors u, v, and z cannot form a basis for 23 because the subspace 23 has a dimension of 3, while the given vectors only span a subspace of dimension 2 (as stated in the information).

3. v, w, and x span a subspace with dimension 3.

This statement is false. The vectors v, w, and x cannot span a subspace with dimension 3 because v and w are part of the subspace spanned by u, v, and w, which has a dimension of 2. Therefore, the span of v, w, and x can have a maximum dimension of 2.

4. u, v, and w are independent.

This statement is true. The information states that u, v, and w span a subspace of dimension 2. If the dimension of the subspace is 2, then any set of vectors that spans that subspace must be independent. Therefore, u, v, and w are independent.

To summarize:

- Statement 1 is false.

- Statement 2 is false.

- Statement 3 is false.

- Statement 4 is true.

Learn more about vector : brainly.com/question/24256726

#SPJ11

The determinant of this matrix will be the value of A that we are solving for.

The given matrix is 3x4, thus to calculate the determinant of this matrix we need to expand along the first row using cofactor expansion.

The steps are as follows:

1. Calculate the determinant of the 2x2 matrix that remains after removing the first row and first column [tex](5 2 -1 | 2 6 3 | -8 -1 7)[/tex] by using the formula a(d) - b(c) = determinant [tex](2x2). (5 x 6 - 2 x 3 = 24)2.[/tex]

Now calculate the determinant of the 2x2 matrix that remains after removing the first row and second column

[tex](2 -1 | 6 7). (2 x 7 - (-1) x 6 = 16)3.[/tex]

Finally, calculate the determinant of the 2x2 matrix that remains after removing the first row and third column

[tex](-8 -1 | 2 6). (-8 x 6 - (-1) x 2 = -46)4.[/tex]

The determinant of the 3x3 matrix is equal to the sum of the product of each element in the first row and its corresponding cofactor, and can be calculated as follows: determinant

[tex]= 5 x 24 - 2 x 16 - (-1) x (-46) \\= 162.5.[/tex]

Now replace the last column with the column containing the constants, to form a 3x3 matrix.

The determinant of this matrix will be the value of A that we are solving for.

Know more about determinant  here:

https://brainly.com/question/24254106

#SPJ11

Two linearly independent solutions of the given differential equation, in the form y₁ = x¹(1 + a₁x + a₂x² + a₃x³ + ...) and y₂ = x²(1 + b₁x + b₂x² + b₃x³ + ...), can be obtained by finding the coefficients using the method of Frobenius

A linearly independent solution cannot be expressed as a linear combination of other solutions. If f(x) and g(x) are nonzero solutions to an equation, they are linearly independent solutions unless you can describe them to each other. Mathematically, we would say that a is no c and k for which the expression.

To find two linearly independent solutions of the given differential equation, let's start by rewriting the equation in a more standard form.

The given equation is: 2x²y - xy + (-x + 1)y = 0

Rearranging the terms, we have: (2x² - x - x + 1)y = 0

Combining like terms, we get: (2x² - 2x + 1)y = 0

Dividing both sides by x², we obtain: 2 - 2/x + 1/x² = 0

Simplifying, we have: 2x² - 2x + 1 = 0

Now, let's find the solutions of this quadratic equation. We can use the quadratic formula:

x = (-b ± √(b² - 4ac)) / (2a)

In this case, a = 2, b = -2, and c = 1. Substituting these values into the quadratic formula, we have:

x = (-(-2) ± √((-2)² - 4(2)(1))) / (2(2))

= (2 ± √(4 - 8)) / 4

= (2 ± √(-4)) / 4

Since the discriminant is negative, there are no real solutions for x. However, we can still find two linearly independent solutions using the method of Frobenius.

Let's assume the solutions have the form:

y₁ = x¹(1 + a₁x + a₂x² + a₃x³ + ...)

y₂ = x²(1 + b₁x + b₂x² + b₃x³ + ...)

Now, let's substitute these forms into the differential equation and solve for the coefficients.

Substituting y = y₁ into the differential equation:

2x²y - xy + (-x + 1)y = 0

2x²(x¹(1 + a₁x + a₂x² + a₃x³ + ...)) - x(x¹(1 + a₁x + a₂x² + a₃x³ + ...)) + (-x + 1)(x¹(1 + a₁x + a₂x² + a₃x³ + ...)) = 0

Simplifying and collecting like terms, we get:

2x³(1 + a₁x + a₂x² + a₃x³ + ...) - x²(1 + a₁x + a₂x² + a₃x³ + ...) + (-x + 1)(x¹(1 + a₁x + a₂x² + a₃x³ + ...)) = 0

Expanding the expressions, we have:

2x³ + 2a₁x⁴ + 2a₂x⁵ + 2a₃x⁶ + ... - x² - a₁x³ - a₂x⁴ - a₃x⁵ - ... + (-x + 1)(x¹ + a₁x² + a₂x³ + a₃x⁴ + ...) = 0

Simplifying further, we get:

2x³ + 2a₁x⁴ + 2a₂x⁵ + 2a₃x⁶ + ... - x² - a₁x³ - a₂x⁴ - a₃x⁵ - ... - x² - a₁x³ - a₂x⁴ - a₃x⁵ - ... + x² + a₁x³ + a₂x⁴ + a₃x⁵ + ... - x + x¹ + a₁x² + a₂x³ + a₃x⁴ + ... = 0

Canceling out terms, we have:

2x³ + 2a₁x⁴ + 2a₂x⁵ + 2a₃x⁶ + ... - x + x¹ + a₁x² + a₂x³ + a₃x⁴ + ... = 0

Grouping like powers of x, we obtain:

(2 - 1)x³ + (2a₁ + 1)x⁴ + (2a₂ + a₁)x⁵ + (2a₃ + a₂)x⁶ + ... = 0

Since this equation must hold for all values of x, the coefficients of each power of x must be zero. Therefore, we have the following equations:

2 - 1 = 0 => a₀ = 1

2a₁ + 1 = 0 => a₁ = -1/2

2a₂ + a₁ = 0 => a₂ = 1/4

2a₃ + a₂ = 0 => a₃ = -1/8

...

Using the same procedure, we can substitute y = y₂ into the differential equation and find the coefficients b₁, b₂, b₃, and so on.

Therefore, two linearly independent solutions of the given differential equation, in the form y₁ = x¹(1 + a₁x + a₂x² + a₃x³ + ...) and y₂ = x²(1 + b₁x + b₂x² + b₃x³ + ...), can be obtained by finding the coefficients using the method of Frobenius.

To learn more about Linear Independent from the given link

https://brainly.com/question/30890315

#SPJ4

The probability that exactly 8 out of the 10 smokers started smoking before 21 is approximately 0.1937, or 19.37% To solve these probability questions, we can use the binomial distribution formula.

a) The probability that a randomly selected smoker started smoking before 21 is 0.9 (as given). We can use the binomial distribution formula: P(X = k) = (n choose k) *[tex]p^k[/tex] * [tex](1 - p)^(n - k)[/tex]

where n is the number of trials, k is the number of successes, p is the probability of success, and (n choose k) represents the binomial coefficient.

In this case, n = 10, k = 8, and p = 0.9. Plugging these values into the formula:

P(X = 8) = [tex](10 choose 8) * 0.9^8 * (1 - 0.9)^(10 - 8)[/tex]

P(X = 8) = [tex](45) * 0.9^8 * 0.1^2[/tex]

P(X = 8) ≈ 0.1937

The probability that exactly 8 out of the 10 smokers started smoking before 21 is approximately 0.1937, or 19.37%.

b) To find this probability, we need to sum up the probabilities of having 8, 9, or 10 smokers who started before 21.

P(X ≥ 8) = P(X = 8) + P(X = 9) + P(X = 10)

Using the binomial distribution formula for each value:

P(X ≥ 8) ≈ 0.1937 + (10 choose 9) * 0.9^9 * 0.1^1 + (10 choose 10) * 0.9^10 * 0.1^0

P(X ≥ 8) ≈ 0.1937 + 0.3874 + 0.3487

P(X ≥ 8) ≈ 0.9298

The probability that at least 8 out of the 10 smokers started smoking before 21 is approximately 0.9298, or 92.98%.

c) To find this probability, we need to sum up the probabilities of having 0 to 7 smokers who started before 21.

P(X < 8) = P(X = 0) + P(X = 1) + ... + P(X = 7)

Using the binomial distribution formula for each value:

P(X < 8) = P(X = 0) + P(X = 1) + P(X = 2) + ... + P(X = 7)

P(X < 8) = 1 - P(X ≥ 8)

Using the result from part b:

P(X < 8) = 1 - 0.9298

P(X < 8) ≈ 0.0702

he probability that fewer than 8 out of the 10 smokers started smoking before 21 is approximately 0.0702, or 7.02%.

d) To find this probability, we need to sum up the probabilities of having 7, 8, and 9 smokers who started before 21.

P(7 ≤ X ≤ 9) = P(X = 7) + P(X = 8) + P(X = 9)

Using the binomial distribution formula for each value:

P(7 ≤ X ≤ 9) = P(X = 7) + P(X = 8) + P(X = 9)

P(7 ≤ X ≤ 9) ≈[tex](10 choose 7) * 0.9^7 * 0.1^3 + 0.1937 + (10 choose 9) * 0.9^9 * 0.1^1[/tex]

P(7 ≤ X ≤ 9) ≈ 0.2668 + 0.1937 + 0.3874

P(7 ≤ X ≤ 9) ≈ 0.8479

The probability that between 7 and 9 (inclusive) out of the 10 smokers started smoking before 21 is approximately 0.8479, or 84.79%.

To know more about Probability  visit-

brainly.com/question/32004014

#SPJ11

Let's solve the problem step by step:

a. To estimate P(E), P(R), and P(D), we can use the given numbers:

P(E) = Number of students admitted early / Total number of early applicants

    = 1,033 / 2,851

    ≈ 0.3622 (rounded to 4 decimals)

P(R) = Number of students rejected outright / Total number of early applicants

    = 854 / 2,851

    ≈ 0.2995 (rounded to 4 decimals)

P(D) = Number of students deferred to regular admissions / Total number of early applicants

    = 964 / 2,851

    ≈ 0.3383 (rounded to 4 decimals)

Therefore, the estimated probabilities are:

P(E) ≈ 0.3622

P(R) ≈ 0.2995

P(D) ≈ 0.3383

b. Events E and D are not mutually exclusive because a student can be admitted early (E) and still be deferred (D) for further consideration. The intersection of E and D (E ∩ D) represents the students who were admitted early and then deferred.

P(E ∩ D) = Number of students admitted early and deferred / Total number of early applicants

         = 0 (as there is no information given about students being admitted early and deferred simultaneously)

Therefore, P(E ∩ D) = 0.

c. To find the probability that a randomly selected student was accepted early or during the regular admission process, we need to consider the total number of students admitted:

Total number of students admitted = Number of students admitted early + Number of students admitted during regular admission

                                = 1,033 + (2,375 - 1,033)  [subtracting the students admitted early from the total class size]

Probability of being accepted early = Number of students admitted early / Total number of students admitted

                                  = 1,033 / 2,375

                                  ≈ 0.4352 (rounded to 4 decimals)

Probability of being accepted during regular admission = Number of students admitted during regular admission / Total number of students admitted

                                                   = (2,375 - 1,033) / 2,375

                                                   ≈ 0.5648 (rounded to 4 decimals)

Therefore, the probabilities are:

Probability of being accepted early ≈ 0.4352

Probability of being accepted during regular admission ≈ 0.5648

Learn more about mutually exclusive here:

https://brainly.com/question/12947901

#SPJ11

Heteroscedasticity refers to the situation where the variance of the error term (u) in a regression model is not constant across different values of the independent variable (X).

How to explain the information

In order to address the problem of heteroscedasticity, there are several approaches:

b The stochastic error term (u) in regression analysis represents the random and unobserved factors that affect the dependent variable (Y) but are not included in the model.

c Cross-sectional data refers to observations collected at a single point in time from different individuals, entities, or subjects. s to analyze their performance. Panel data (also known as longitudinal or time-series cross-sectional data) refers to a combination of cross-sectional and time series data.

d The classical linear regression model makes several assumptions. These assumptions are important for the validity and reliability of the ordinary least squares (OLS) estimator. The necessary assumptions for ensuring the unbiasedness of the OLS estimator are:

Learn more about regression on

https://brainly.com/question/25987747

#SPJ4

To find the variable parameters u₁, u₂, and u₃, we substitute Yp = U₁(x)e^(-x) + U₂(x)e^x + U₃(x)e^(2x) into the given differential equation. By equating the coefficients of the exponential terms, we obtain three second-order linear homogeneous differential equations. Solving these equations will yield the values of u₁, u₂, and u₃, which satisfy the original differential equation.

To find the variable parameters u₁, u₂, and u₃ that make Yp = U₁(x)e^(-x) + U₂(x)e^x + U₃(x)e^(2x) a particular solution of the differential equation, we need to substitute Yp into the differential equation and solve for the unknown functions U₁(x), U₂(x), and U₃(x).

Given the differential equation: y" - 2y" - y' + 2y = e^(3x),

We differentiate Yp with respect to x:

Yp' = U₁'(x)e^(-x) + U₂'(x)e^x + U₃'(x)e^(2x)

Yp" = U₁"(x)e^(-x) + U₂"(x)e^x + U₃"(x)e^(2x)

Substituting these derivatives into the differential equation:

[U₁"(x)e^(-x) + U₂"(x)e^x + U₃"(x)e^(2x)] - 2[U₁'(x)e^(-x) + U₂'(x)e^x + U₃'(x)e^(2x)] - [U₁'(x)e^(-x) + U₂'(x)e^x + U₃'(x)e^(2x)] + 2[U₁(x)e^(-x) + U₂(x)e^x + U₃(x)e^(2x)] = e^(3x)

Next, we group the terms with the same exponential factors:

[e^(-x)(U₁"(x) - 2U₁'(x) - U₁'(x) + 2U₁(x))] + [e^x(U₂"(x) - 2U₂'(x) - U₂'(x) + 2U₂(x))] + [e^(2x)(U₃"(x) - 2U₃'(x) - U₃'(x) + 2U₃(x))] = e^(3x)

Now, equating the corresponding coefficients of the exponential terms on both sides of the equation, we get:

U₁"(x) - 4U₁'(x) + 2U₁(x) = 0 (for e^(-x) term)

U₂"(x) - 4U₂'(x) + 2U₂(x) = 0 (for e^x term)

U₃"(x) - 4U₃'(x) + 2U₃(x) = e^(3x) (for e^(2x) term)

These are second-order linear homogeneous differential equations for U₁(x), U₂(x), and U₃(x) respectively. Solving these equations will give us the variable parameters u₁, u₂, and u₃ that satisfy the original differential equation.

To learn more about differential equation visit : https://brainly.com/question/1164377

#SPJ11

To solve the integral ∫∫∫ f(x, y, z) dz dy dx, where the limits of integration are as follows: 1 ≤ x ≤ 0, 3 - 3x ≤ y ≤ 0, and 9 - y^2 ≤ z ≤ 0, we need to change the order of integration to dx dy dz.

The given limits of integration define a region in three-dimensional space. To determine the new limits of integration, we need to analyze the intersection of the three inequalities.

First, let's consider the limits for z. We have 0 ≤ z ≤ 9 - y^2.

Next, we consider the limits for y. We have 3 - 3x ≤ y ≤ 0. Since y depends on x, we need to determine the range of x that satisfies this inequality. Solving 3 - 3x ≤ 0, we find x ≤ 1. Therefore, the limits for y are determined by x and become 3 - 3x ≤ y ≤ 0.

Lastly, we consider the limits for x. We have 1 ≤ x ≤ 0.

Now we can rewrite the integral in the order of dx dy dz:

∫ from 1 to 0 ∫ from 3 - 3x to 0 ∫ from 9 - y^2 to 0 f(x, y, z) dz dy dx

Note that when changing the order of integration, we reverse the order of the variables and their limits.

The new integral becomes:

∫ from -3 to 3 ∫ from 0 to 9 - y^2 ∫ from 0 to 3 - (1/3)x f(x, y, z) dz dx dy

This new order of integration allows us to evaluate the integral with respect to x first, then y, and finally z, using the respective limits of integration.

To know more about integration visit-

brainly.com/question/31584953

#SPJ11

To find the Maclaurin series for the function F(x) = ln((x + 3)(x + 3)²), we can start by expanding the natural logarithm using its Taylor series representation:

ln(1 + t) = t - (t²/2) + (t³/3) - (t⁴/4) + ...

We substitute t = x + 3 and apply this expansion to each factor in F(x):

F(x) = ln((x + 3)(x + 3)²)

= ln(x + 3) + ln(x + 3)²

Now, let's expand ln(x + 3) using its Maclaurin series:

ln(x + 3) = ln(1 + (x - (-3)))

= (x - (-3)) - ((x - (-3))²/2) + ((x - (-3))³/3) - ..

To simplify the expression, we replace x - (-3) with x + 3:

ln(x + 3) = (x + 3) - ((x + 3)²/2) + ((x + 3)³/3) - ...

Now, let's expand ln(x + 3)² using the binomial theorem:

ln(x + 3)² = 2ln(x + 3)

= 2[((x + 3) - ((x + 3)²/2) + ((x + 3)³/3) - ...]

Multiplying these expansions together, we get:

F(x) = [(x + 3) - ((x + 3)²/2) + ((x + 3)³/3) - ...] + 2[((x + 3) - ((x + 3)²/2) + ((x + 3)³/3) - ...]

Now, let's collect like terms and simplify the expression:

F(x) = [3 + (2/3)(x + 3) + (2/3)(x + 3)² + ...]

Expanding further, we have:

F(x) = 3 + (2/3)(x + 3) + (2/3)(x² + 6x + 9) + ...

Simplifying and taking the first three terms:

F(x) ≈ 3 + (2/3)x + 2x²/3 + 2x/3 + 6/3

≈ 9/3 + 2x/3 + 2x²/3

≈ (2/3)(x² + x + 3)

Therefore, the first three terms of the Maclaurin series for F(x) = ln((x + 3)(x + 3)²) are (2/3)(x² + x + 3).

Learn more about Maclaurin series  here:

https://brainly.com/question/31308619

#SPJ11

The solution is given by x(t) = (2/5)t and y(t) = (5/4)cos(4t/5) + (25/4)sin(4t/5). To convert the given system into a second-order differential equation in y, we differentiate the second equation with respect to t and substitute x from the first equation.

Given, the system of differential equations is:dr/dt = 5ydy/dt = (3r - 8y)/(5y).

Using quotient rule, we differentiate the second equation with respect to t. We get: d²y/dt² = [(15y)(3r' - 8y) - (3r - 8y)(5y')]/(5y)².

Differentiating the first equation with respect to t, we get:r' = 5y'. Also, from the first equation, we have:x = r/5.

Therefore, r = 5x. Substituting these values in the second-order differential equation, we get:d²y/dt² = (3/5)dx/dt - (24/25)y.

Simplifying, we get:d²y/dt² = (3/5)x' - (24/25)y

Solving the above equation using initial conditions y(0) = 5 and y'(0) = 2, we get: y(t) = (5/4)cos(4t/5) + (25/4)sin(4t/5)

Using the first equation and initial conditions x(0) = 0 and x'(0) = r'(0)/5 = 2/5, we get: x(t) = (2/5)t

Therefore, the required values are: x(t) = (2/5)t and y(t) = (5/4)cos(4t/5) + (25/4)sin(4t/5).

Thus, the solution is given by x(t) = (2/5)t and y(t) = (5/4)cos(4t/5) + (25/4)sin(4t/5).

To know more about Quotient rule visit-

brainly.com/question/30278964

#SPJ11

The area left over after the barn is built is 54,125 m².

Given that, A rectangular field is 130 m by 420 m. A rectangular barn 19 m by 25 m is built in the field.

The total area of the rectangular field is 130 m x 420 m = 54,600 m².

The area of the rectangular barn is 19 m x 25 m = 475 m².

The area left over after the barn is built is

54,600 m² - 475 m² = 54,125 m²

Therefore, the area left over after the barn is built is 54,125 m².

Learn more about the area here:

https://brainly.com/question/27683633.

#SPJ1

The required answers are:

a. The limit of the sequence [tex]x_n[/tex] is [tex](e^t) / (t + 1)[/tex].

b. [tex]q_n[/tex] converges to [tex]l^2[/tex].

c. If [tex]y_n[/tex] converges to I, then the subsequence [tex]a_n[/tex] will also converge to I, as it consists of every second element of [tex]y_n[/tex].

d. The given  sequence can have at most one limit.

e, The value of the limit for the sequence 1 is 1

To find the limit of the sequence[tex]x_n = (e^t * n^3) / (t^2+ 3n + (t + 1)n^3)[/tex], we need to analyze its behavior as n approaches infinity. Let's consider the expression inside the sequence:

[tex]x_n = (e^t * n^3) / (t^2+ 3n + (t + 1)n^3)[/tex],

As n tends to infinity, the highest power term in the numerator and denominator dominates the expression. In this case, the dominant term is n³ in both the numerator and denominator.

Dividing both the numerator and denominator by n³, we have:

[tex]x_n = (e^t * (n^3/n^3)) / (t^2/n^3 + 3n/n^3 + (t + 1)n^3/n^3)[/tex]

[tex]= (e^t) / (t^2/n^3 + 3/n^2 + (t + 1))[/tex]

As n approaches infinity, the terms [tex]t^2/n^3[/tex] and [tex]3/n^2[/tex] tend to zero since the denominator grows faster than the numerator. Therefore,  simplify the expression further:

[tex]\lim_(n\to\infty) x_n = (e^t) / (0 + 0 + (t + 1))[/tex]

[tex]= (e^t) / (t + 1)[/tex]

Hence, the limit of the sequence [tex]x_n[/tex] is [tex](e^t) / (t + 1).[/tex]

(b) If [tex]y_n[/tex] converges to l, the limit of [tex]y_n[/tex] , then [tex]q_n[/tex], which is [tex](y_n)^2[/tex], will converge to [tex]l^2[/tex].

Therefore, [tex]q_n[/tex] converges to [tex]l^2[/tex].

(c) The subsequence [tex]a_n[/tex] consists of every second element of[tex]y_n[/tex], i.e., [tex]a_k = y_{2k}[/tex]. Let's write down the first four elements of an:

[tex]a_1 = y_2(1) = y_2 = e^{2 [2(1) - 2(t + 2)]} = e^{-4(t + 2)}[/tex]

[tex]a_2 = y_2(2) = y_4 = e^{2 [2(2) - 2(t + 2)]} = e^{-8(t + 2)}[/tex]

[tex]a_3 = y_2(3) = y_6 = e^{2 [2(3) - 2(t + 2)]} = e^{-12(t + 2)}[/tex]

[tex]a_4 = y_2(4) = y_8 = e^{2 [2(4) - 2(t + 2)]} = e^{-16(t + 2)}[/tex]

If [tex]y_n[/tex] converges to I, then the subsequence [tex]a_n[/tex] will also converge to I, as it consists of every second element of [tex]y_n[/tex].

(d) To prove the statement that a sequence can have at most one limit, we assume the contrary. Assume that a sequence has two distinct limits, [tex]L_1[/tex] and [tex]L_2[/tex], where [tex]L_1 \neq L_2[/tex]

_2.

If a sequence has a limit [tex]L_1[/tex] , it means that for any positive value ε, there exists a positive integer N1 such that for all n > N1,

|xn - L1| < ε.

Similarly, if a sequence has a limit  [tex]L_2[/tex], there exists a positive integer N2 such that for all n > N2, [tex]|x_n - L_2| < \epsilon[/tex]

Now, let N = max(N1, N2). For this value of N, we have:

[tex]|x_n - L_1| < \epsilon[/tex](for all n > N)

[tex]|x_n - L_2| < \epsilon[/tex] (for all n > N)

By combining these inequalities, we have:

[tex]|L_1 - L_2| = |L_1 - x_n + x_n - L_2|[/tex]

[tex]\leq |L_1 - x_n| + |x_n - L_2|[/tex]

[tex]< 2\epsilon[/tex]

Since ε can be any positive value, it follows that |L_1 - L_2| can be made arbitrarily small. However, since L_1 ≠ L_2, this is a contradiction.

Therefore, the assumption that a sequence can have two distinct limits is false, and a sequence can have at most one limit.

(e) Based on the conclusion in part (d) that a sequence can have at most one limit, it implies that the subsequence [tex]a_k[/tex] and [tex]q_n[/tex] cannot converge to two different limits.

Therefore, if the limit 1 is valid for one of the sequences, it must also be the limit for the other sequence.

Thus, the value of the limit for the sequence 1 is 1.

Hence, the required answers are:

a. The limit of the sequence [tex]x_n[/tex] is [tex](e^t) / (t + 1)[/tex].

b. [tex]q_n[/tex] converges to [tex]l^2[/tex].

c. If [tex]y_n[/tex] converges to I, then the subsequence [tex]a_n[/tex] will also converge to I, as it consists of every second element of [tex]y_n[/tex].

d. The given  sequence can have at most one limit.

e, The value of the limit for the sequence 1 is 1

Know more about limit of sequence here:

https://brainly.com/question/16779166

#SPJ4

Variance = 1.583

Standard deviation = 1.258

Given ,

sample = 1 2 3 4

frequency =  3 5 1 2

Now,

Firstly,

Variance of sample :

S² = 1/n-1 ∑ ( observation in the sample - Sample mean)²

S² = Sample variance

n = Number of observations in sample

Xi=  observation in the sample

x = Sample mean

S² = 1/(4-1) [ ( 1 - 2.5 )² + (2 - 2.5)² + (3 - 2.5)² + (4 - 2.5)² ]

S² = 1.583

S = 1.258

Thus,

Variance and standard deviation of the sample are 1.583 and 1.258 respectively .

Know more about variance,

https://brainly.com/question/16686665

#SPJ4

(a) (2x + 1) multiplied by the integral of x + 3 with respect to x, (b) the integral of √(r + 3) multiplied by 4x multiplied by[tex]e^x[/tex] and (c) 2c multiplied by the second derivative of [tex]t^2[/tex] with respect to t.

In the first part, the expression (2x + 1) represents a linear equation multiplied by the integral of x + 3 with respect to x. This requires finding the antiderivative of x + 3, which results in [tex](1/2)x^2 + 3x[/tex]. The final result can be obtained by multiplying this antiderivative by the linear equation (2x + 1).

In the second part, the expression √(r + 3) represents the square root of the quantity (r + 3). The integral involves the product of 4x and e raised to the power of x, which implies finding the antiderivative of this product with respect to x. Once the antiderivative is determined, it is multiplied by the square root of (r + 3) to obtain the final result.

In the third part, the expression 2 multiplied by c represents a constant multiplied by the second derivative of t squared with respect to t. To calculate this, we need to find the second derivative of t squared with respect to t, which results in 2. Multiplying this by the constant 2c yields the final answer

Kearn more about integral

brainly.com/question/31059545

#SPJ11

The final result of the double integral ∫∫R ln(xy)/y dA over the region R = {(x, y) | 1 ≤ x ≤ 3, 2 ≤ y ≤ 5} is : (3 ln(3) - 2) [(ln(5))^2 - (ln(2))^2]/2

To evaluate the double integral ∫∫R ln(xy)/y dA over the region R = {(x, y) | 1 ≤ x ≤ 3, 2 ≤ y ≤ 5}, we need to compute the iterated integral.

The integral can be written as:

∫∫R ln(xy)/y dA = ∫[2,5] ∫[1,3] ln(xy)/y dxdy

Let's evaluate this integral step by step:

∫[1,3] ln(xy)/y dx

To evaluate this integral with respect to x, treat y as a constant and integrate ln(xy)/y with respect to x:

= ∫[1,3] (1/y) ln(xy) dx

Using the property ln(ab) = ln(a) + ln(b), we can rewrite the integrand:

= (1/y) ∫[1,3] ln(x) + ln(y) dx

Since ln(y) is a constant with respect to x, we can factor it out of the integral:

= (ln(y)/y) ∫[1,3] ln(x) dx

Now we can integrate ln(x) with respect to x:

= (ln(y)/y) [x ln(x) - x] | [1,3]

Plugging in the limits of integration:

= (ln(y)/y) [(3 ln(3) - 3) - (ln(1) - 1)]

Since ln(1) = 0, the expression simplifies to:

= (ln(y)/y) (3 ln(3) - 2)

Now we integrate this expression with respect to y from 2 to 5:

∫[2,5] (ln(y)/y) (3 ln(3) - 2) dy

= (3 ln(3) - 2) ∫[2,5] (ln(y)/y) dy

To integrate (ln(y)/y) with respect to y, we can use u-substitution:

Let u = ln(y), then du = (1/y) dy

The integral becomes:

= (3 ln(3) - 2) ∫[ln(2), ln(5)] u du

Integrating u with respect to u gives us:

= (3 ln(3) - 2) [(u^2)/2] | [ln(2), ln(5)]

Plugging in the limits of integration:

= (3 ln(3) - 2) [((ln(5))^2)/2 - ((ln(2))^2)/2]

Simplifying further:

= (3 ln(3) - 2) [(ln(5))^2 - (ln(2))^2]/2

Learn more about integral here:

https://brainly.com/question/27360126

#SPJ11

It will take approximately 3.4 hours for the number of bacteria to reach 2400 (rounded to the nearest tenth).

The function is: `P(h) = 1600(2.184)h. The number of bacteria P(h) in a certain population increases according to the following function, where time h is measured in hours. P() = 1600(2.184)h

The number of bacteria P(h) is given as 2400. We need to calculate  the value of h for which the number of bacteria P(h) is 2400.

P(h) = 1600(2.184)

h2400 = 1600(2.184)h

Dividing both sides by 1600, we get: `2.184h = 1.5`

Taking the natural logarithm of both sides, we get: `ln(2.184h) = ln 1.5`. Using the property `ln aᵇ = b ln a`, we get:` h ln 2.184 = ln 1.5`. Dividing both sides by ln 2.184, we get: `h = ln 1.5 / ln 2.184`

Now, we'll use a calculator to find the value of h:`h ≈ 3.4`

You can learn more about bacteria at: brainly.com/question/15490180

#SPJ11