y=x2+3x+1 has how many real roots?

Answer:

$36 is the correct answer.

Step-by-step explanation:

Given that:

Adam has $15 of a certain type of rare coin.

$5 of this type of rare coins are equivalent to $12.

To find:

The total worth of $15 of rare coins = ?

If value of each coin is same.

Solution:

We are given that value of each coin is same.

So, We can simply use unitary method to find out the total worth of $15 of rare coins.

i.e. we first find out what is the worth of $1 of rare coins and then we find the worth of total required quantity.

Given that

$5 of rare coins are worthy of = $12

$1 of rare coins are worthy of = [tex]\frac{12}{5}[/tex]

$15 of rare coins are worthy of =

[tex]\\\dfrac{12}{5}\times 15\\\Rightarrow \dfrac{12\times 15}{5}\\\Rightarrow 12\times 3\\\Rightarrow \$36[/tex]

[tex]\therefore[/tex] $15 of rare coins are worth of $36.

Answer:

[tex]t=\frac{201.77-200}{\frac{2.41}{\sqrt{10}}}=2.32[/tex]    

The degrees of freedom are given by:

[tex]df=n-1=10-1=9[/tex]  

The p value for this case is given by:

[tex]p_v =2*P(t_{(9)}>2.32)=0.0455[/tex]    

For this case since the p value is lower than the significance level we have enough evidence to reject the null hypothesis and we can conclude that the true mean is significantly different from 200 F.

Step-by-step explanation:

Information given

data: 202.2 203.4 200.5 202.5 206.3 198.0 203.7 200.8 201.3 199.0

We can calculate the sample mean and deviation with the following formulas:

[tex]\bar X= \frac{\sum_{i=1}^n X_i}{n}[/tex]

[tex]\sigma=\sqrt{\frac{\sum_{i=1}^n (X_i -\bar X)^2}{n-1}}[/tex]

[tex]\bar X=201.77[/tex] represent the sample mean    

[tex]s=2.41[/tex] represent the sample standard deviation    

[tex]n=10[/tex] sample size    

[tex]\mu_o =200[/tex] represent the value that we want to test    

[tex]\alpha=0.05[/tex] represent the significance level for the hypothesis test.    

t would represent the statistic

[tex]p_v[/tex] represent the p value for the test

Hypothesis to test

We want to determine if the true mean is equal to 200, the system of hypothesis are :    

Null hypothesis:[tex]\mu = 200[/tex]    

Alternative hypothesis:[tex]\mu = 200[/tex]    

The statistic for this case is given by:

[tex]t=\frac{\bar X-\mu_o}{\frac{s}{\sqrt{n}}}[/tex] (1)    

The statistic is given by:

[tex]t=\frac{201.77-200}{\frac{2.41}{\sqrt{10}}}=2.32[/tex]    

The degrees of freedom are given by:

[tex]df=n-1=10-1=9[/tex]  

The p value for this case is given by:

[tex]p_v =2*P(t_{(9)}>2.32)=0.0455[/tex]    

For this case since the p value is lower than the significance level we have enough evidence to reject the null hypothesis and we can conclude that the true mean is significantly different from 200 F.

Answer:

Step-by-step explanation:

Let x represent the number of friends that Monica asked to a charity raffle ticket. If all but 4 of her friends bought a ticket, it means that only 4 of her friends did not buy the charity raffle ticket. Thus, the number of her friends that bought the charity raffle ticket is

x - 4

If each ticket costs $3 and the total amount that was raised is $18, then algebraic expression representing the number of friends that Monica asked is

3(x - 4) = 18

3x - 12 = 18

3x = 18 + 12 = 30

x = 30/3 = 10

Monica asked 10 friends

Answer:

Step-by-step explanation:

This problem bothers on permutation

Given the letters LEARN

The total alphabets are 5 in numbers

Since there are no repeating letters, and there are 5 total letters, there are 5!=5*4*3*2*1=  120 ways to arrange them

Answer:

Step-by-step explanation:

5x(x + 3) + 6(x + 3)

The final answer is

( 5x + 6 ) ( x + 3 )

Hope this helps you

Answer:

48.3 cm²

Step-by-step explanation:

Let A be the area of the yellow region

A= the area of the square - the area of the quarter square

A= 15²-(15²*π)/4= 48.28≈ 48.3 cm²

We have

[tex]\displaystyle \sum_{n=1}^\infty \frac{n}{n^2+8} < \int_1^\infty \frac{x}{x^2+8}\,\mathrm dx[/tex]

For the integral, substitute y = x ² + 8 and dy = 2x dx. Then

[tex]\displaystyle \int_1^\infty \frac{x}{x^2+8}\,\mathrm dx = \frac12 \int_9^\infty \frac{\mathrm dy}y = \frac12 \ln(y)\bigg|_{y=9}^{y\to\infty} = \infty[/tex]

The integral diverges, so the sum also diverges by the integral test.

Answer:

The relationship between the areas of the three squares is that square A plus square B equals the area of square C.

The sum of the square of a and b is equal to the area of square of c

Data;

This theorem is used to calculated a missing side from a right angle triangle when we have the value of at least two sides.

Given that

[tex]c^2 = a^2 + b^2[/tex]

This indicates a relationship such that the sum of square of two sides is equal to the area of the square of one side. I.e the area of the square of c is equal to the sum of the square of both a and b.

Learn more on Pythagoras Theorem here;

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Answer:

a) 26.33 kg/d and 29.67 kg/d

b) 94.5%

Step-by-step explanation:

a. Find a 99% confidence interval for the true mean milk production.

We have that to find our [tex]\alpha[/tex] level, that is the subtraction of 1 by the confidence interval divided by 2. So:

[tex]\alpha = \frac{1-0.99}{2} = 0.005[/tex]

Now, we have to find z in the Ztable as such z has a pvalue of [tex]1-\alpha[/tex].

So it is z with a pvalue of [tex]1-0.005 = 0.995[/tex], so [tex]z = 2.575[/tex]

Now, find the margin of error M as such

[tex]M = z*\frac{\sigma}{\sqrt{n}}[/tex]

In which [tex]\sigma[/tex] is the standard deviation of the population and n is the size of the sample.

[tex]M = 2.575*\frac{2.25}{\sqrt{12}} = 1.67[/tex]

The lower end of the interval is the sample mean subtracted by M. So it is 28 - 1.67 = 26.33 kg/d

The upper end of the interval is the sample mean added to M. So it is 28 + 1.67 = 29.67 kg/d

The 99% confidence interval for the true mean milk production is between 26.33 kg/d and 29.67 kg/d

b. If the farms want the confidence interval to be no wider than ± 1.25 kg/d, what level of confidence would they need to use?

We need to find z initially, when M = 1.25.

[tex]M = z*\frac{2.25}{\sqrt{12}} = 1.67[/tex]

[tex]1.25 = z*\frac{2.25}{\sqrt{12}} = 1.67[/tex]

[tex]2.25z = 1.25\sqrt{12}[/tex]

[tex]z = \frac{1.25\sqrt{12}}{2.25}[/tex]

[tex]z = 1.92[/tex]

When [tex]z = 1.92[/tex], it has a pvalue of 0.9725.

1 - 2*(1 - 0.9725) = 0.945

So we should use a confidence level of 94.5%.

The correct answer is Graph B

Explanation:

The purpose of histograms is to display visually the frequency of a variable. Additionally, a higher bar represents a higher frequency.

According to this, the correct histogram is graph B because in this the frequencies for each batting average are displayed correctly. For example, the highest bar is related to the average 0.330-0.339, which has the highest frequency (28), this is followed in height by the bar that represents a frequency of 24 and is related to the average 0.340-0.349.

At the same time, the averages 0.320-0.329 and 0.360-0.369 that have a frequency of 2 are represented through the shortest bars, while the average 0.350-0.359 with a frequency of 4 is related to a bar with exactly the double of heigh than those with a frequency of 2.

Answer:

graph B

Step-by-step explanation:

what happened to your screen

The value of the expression when simplified is -13

It is important to note:

PEDMAS is a mathematical acronym that representing;

Also, we should note that absolute value of a number is the non-negative value of that number. It s the value of a number irrespective of its direction from zero.

It is denoted with the symbol '| |'

Given the expression;

|2-5|-(12 ÷4-1)^2

Solve the bracket

|-3| - (12 /3)^2

Solve further

|-3| - 4^2

Find the absolute value

3 - 4^2

Find the square

3 - 16

-13

The value is - 13

Thus, the value of the expression when simplified is -13

Learn more about PEDMAS here:

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Answer:  x = -10

Step-by-step explanation:

see image

A) congruent sides implies congruent angles A = 64°

B) Use the Triangle Sum Theorem: 64° + 64° + B = 180° --> B = 52°

C) B and C are complimentary angles: 52° + C = 90°  --> C = 38°

D) Use the Triangle Sum Theorem knowing that congruent sides implies congruent angles: 38° + 2D = 180°  --> D = 71°

∠2) D and ∠2 are supplementary angles: 71° + ∠2 = 180°  --> ∠2 = 109°

Solve for x:

109° = x + 119

 -10  = x

Answer:

x = -10

Step-by-step explanation:

Find the measure of angle m∠2

The triangles are isosceles triangles, the base angles are equal.

The other base angle is also 64°.

Using Triangle Sum Theorem.

64 + 64 + y = 180

y = 52

The top angle is 52°.

The whole angle is 90°.

90 - 52 = 38

The second triangle has base angles equal.

Using Triangle Sum Theorem.

38 + z + z = 180

z = 71

The two base angles are 71°.

Angles on a straight line add up to 180°.

71 + m∠2 = 180

m∠2 = 109

The measure of m∠2 is 109°

Find the value of x

m∠2 = x + 119

109 = x + 119

x = 109 - 119

x = -10

Answer:

3.025

Step-by-step explanation:

3.4-1/2(0.75)

3.4-0.375

3.025

Answer:

Range = [- 2.5, 0.5] = [ - 5/2, 1/2]

Step-by-step explanation:

Smallest value of cos α = - 1,

largest value of cos α = 1.

When cos 4x = - 1,  y=3/2cos4x-1 = 3/2*(-1) - 1 = - 5/2 = - 2 1/2 = - 2.5

When cos 4x = 1,  y=3/2cos4x-1 = 3/2*1 - 1 = 1/2 = 0.5

Range = [- 2.5, 0.5] = [ - 5/2, 1/2]

u/4 - 4 = -20

Add 4 to both sides:

u/4 = -16

Multiply both sides by 4:

u = -64

Answer:

u=-64

Step-by-step explanation:

u/4 -4 = -20

First add 4 to both sides.

u/4=-16

Now multiply both sides by 4

u=-64

Your answer is the second option, she should choose the rectangular tiles because the total cost will be $8 less.

To find this answer we need to first find the total cost for using square tiles, and the cost for using rectangular tiles, and compare them. We can do this by finding the area of each tile individually, calculating how many tiles we would need, and multiplying this by the cost for one tile:

Square tiles:

The area of one square tile is 1/2 × 1/2 = 1/4 ft. Therefore we need 40 ÷ 1/4 = 160 tiles. If each tile costs $0.45, this means the total cost will be $0.45 × 160 = $72

Rectangular tiles:

The area of one rectangular tile is 2 × 1/4 = 2/4 = 1/2 ft. Thus we need 40 ÷ 1/2 = 80 tiles. Each tile costs $0.80, so the total cost will be 80 × $0.80 = $64.

This shows us that the rectangular tiles will be cheaper by $8.

I hope this helps! Let me know if you have any questions :)

Answer:

B

Step-by-step explanation:

E2020 : )

Answer:

a) [tex]f^{-1} (x) = \frac{1}{2} Cos^{-1} (\frac{x-1}{3} ) +\frac{3}{2}[/tex]

The inverse of given function

[tex]f^{-1} (x) = \frac{1}{2} Cos^{-1} (\frac{x-1}{3} ) +\frac{3}{2}[/tex]

Step-by-step explanation:

Step(i):-

Given function f(x) = 3 cos (2 x -3) + 1

Let y = f(x) = 3 cos (2 x -3) + 1

     y = 3 cos (2 x -3) + 1

   ⇒ y - 1 =  3 cos (2 x -3)

   ⇒   [tex]cos ( 2 x - 3 ) =\frac{y -1}{3}[/tex]

  ⇒[tex]cos ^{-1} ( cos (2 x - 3)) = Cos^{-1} (\frac{y-1}{3} )[/tex]

We know that inverse trigonometric equations

cos⁻¹(cosθ) = θ

[tex]2 x - 3 = Cos^{-1} (\frac{y-1}{3} )[/tex]

[tex]2 x = Cos^{-1} (\frac{y-1}{3} ) +3[/tex]

[tex]x = \frac{1}{2} Cos^{-1} (\frac{y-1}{3} ) +\frac{3}{2}[/tex]

Step(ii):-

we know that   y= f(x)

The inverse of the given function

                         [tex]x = f^{-1} (y)[/tex]

                    [tex]f^{-1} (y) = \frac{1}{2} Cos^{-1} (\frac{y-1}{3} ) +\frac{3}{2}[/tex]

The inverse of given function in terms of 'x'

                     [tex]f^{-1} (x) = \frac{1}{2} Cos^{-1} (\frac{x-1}{3} ) +\frac{3}{2}[/tex]

conclusion:-

 The inverse of given function

[tex]f^{-1} (x) = \frac{1}{2} Cos^{-1} (\frac{x-1}{3} ) +\frac{3}{2}[/tex]

Answer:

See Explanation

Step-by-step explanation:

[tex]f(x) = 4 - 6x + 3 {x}^{2}...(1) \\ plug \: x = a \: in \: (1) \\ f(a) = \boxed{ 4 - 6a + 3 {a}^{2} } \\ \\ next \: plug \: x = (a + h) \: in \: (1) \\ f(a + h) = 4 - 6(a + h) + 3 {(a + h)}^{2} \\ = 4 - 6a - 6h + 3( {a}^{2} + {h}^{2} + 2ah) \\ = 4 - 6a - 6h + 3 {a}^{2} + 3{h}^{2} + 6ah \\ f(a + h) = \boxed{3 {a}^{2} + 3{h}^{2} + 6ah - 6a - 6h + 4} \\ \\ now \\ \\ \frac{f(a + h) - f(a)}{h} \\ \\ = \frac{(3 {a}^{2} + 3{h}^{2} + 6ah - 6a - 6h + 4) -(4 - 6a + 3 {a}^{2} ) }{h} \\ \\ = \frac{3 {a}^{2} + 3{h}^{2} + 6ah - 6a - 6h + 4 -4 + 6a - 3 {a}^{2} }{h} \\ \\ = \frac{ 3{h}^{2} + 6ah - 6h }{h} \\ \\ = \frac{3h( {h} + 2a - 2) }{h} \\ \\ \frac{f(a + h) - f(a)}{h} = \boxed{ 3( 2a + h - 2)}[/tex]

Answer:

3ab

Step-by-step explanation:

area = length * width

width = area/length

width = (12ab^2)/(4b)

width = 3ab

Expand everything in the limit:

[tex]\displaystyle\lim_{h\to0}\frac{(-7+h)^2-49}h=\lim_{h\to0}\frac{(49-14h+h^2)-49}h=\lim_{h\to0}\frac{h^2-14h}h[/tex]

We have [tex]h[/tex] approaching 0, and in particular [tex]h\neq0[/tex], so we can cancel a factor in the numerator and denominator:

[tex]\displaystyle\lim_{h\to0}\frac{h^2-14h}h=\lim_{h\to0}(h-14)=\boxed{-14}[/tex]

Alternatively, if you already know about derivatives, consider the function [tex]f(x)=x^2[/tex], whose derivative is [tex]f'(x)=2x[/tex].

Using the limit definition, we have

[tex]f'(x)=\displaystyle\lim_{h\to0}\frac{f(x+h)-f(x)}h=\lim_{h\to0}\frac{(x+h)^2-x^2}h[/tex]

which is exactly the original limit with [tex]x=-7[/tex]. The derivative is [tex]2x[/tex], so the value of the limit is, again, -14.

Answer:

Rounded to two decimals the regression curve is:

[tex]y=-0.70\,x^2+2.37\,x+11.96[/tex]

Step-by-step explanation:

The objective of this problem is to have you use a calculator and enter the data in to separate lists: one containing the x-values, and the other the correspondent y-values (following the same order).

Once the data is entered, you need to access the regression tool and request a quadratic form of regression.

You should get and image and resulting function as shown in the attached image.

Answer:

Rounded to two decimals the regression curve is:

Step-by-step explanation:

Answer:

2317.44

Step-by-step explanation:

Solution for What is 408 percent of 568:

408 percent *568 =

(408:100)*568 =

(408*568):100 =

231744:100 = 2317.44

Answer:

2317.44

Step-by-step explanation:

Answer:

Step-by-step explanation:

x-y=3

-y=3-x

y=x-3

when x=3 y=0

when x=1 y=-2

when x=2 y=-1

Answer:

A = x² + 9x + 8

Step-by-step explanation:

Area of Parallelogram Formula: A = bh

We are given b = x + 8 and h = x + 1, so simply plug it in:

A = (x + 8)(x + 1)

A = x² + x + 8x + 8

A = x² + 9x + 8

━━━━━━━☆☆━━━━━━━

▹ Answer

A = x² + 9x + 8

▹ Step-by-Step Explanation

A = bh

A = (x + 8) * (x + 1)

A = x² + 9x + 8

Hope this helps!

- CloutAnswers ❁

Brainliest is greatly appreciated!

━━━━━━━☆☆━━━━━━━

Answer:

The answer is "Option C"

Step-by-step explanation:

Answer:

2m + 1

Step-by-step explanation:

Simply combine like terms. m terms go with m terms and constants go with constants.

Answer:

2m + 1

Step-by-step explanation:

3m + 1 - m =

= 3m - m + 1

= 2m + 1

Answer: Yes

Step-by-step explanation:

First multiply the first equation by three to get 3x+12y=69

Then subtract 12y from both sides of the second equation

Then add the first system and the second like this:

[tex]3x+12y=69\\-3x-12y=1\\--------\\0+0=70\\0=70[/tex]

Because 0≠70, the system has no solutions

━━━━━━━☆☆━━━━━━━

▹ Answer

(-1, 3)

▹ Step-by-Step Explanation

y - 4x = 7

2y + 4x = 2

Substitute

y - (2 - 2y) = 7

Solve

y = 3

Substitute

4x = 2 - 2 * 3

Solve

x = -1

Final Answer

(x, y) = (-1, 3)

Hope this helps!

- CloutAnswers ❁

Brainliest is greatly appreciated!

━━━━━━━☆☆━━━━━━━

Answer:

D: (-1,3)

Edg 2020

Answer:

y=6x+18

Step-by-step explanation:

Answer:

y = 6x - 30

Step-by-step explanation:

The slope is 6.

Use the formula for the equation of a line.

y = mx + b

Where m is the slope, and b is the y-intercept.

y = 6x + b

The point is given (4, -6)

                               (x , y)

Put x as 4, y as -6.

-6 = 6(4) + b

-6 = 24 + b

-6 - 24 = b

-30 = b

The y-intercept is -30.

The equation of the line is y = 6x - 30.

For the ODE

[tex]ty'+2y=\sin t[/tex]

multiply both sides by t so that the left side can be condensed into the derivative of a product:

[tex]t^2y'+2ty=t\sin t[/tex]

[tex]\implies(t^2y)'=t\sin t[/tex]

Integrate both sides with respect to t :

[tex]t^2y=\displaystyle\int t\sin t\,\mathrm dt=\sin t-t\cos t+C[/tex]

Divide both sides by [tex]t^2[/tex] to solve for y :

[tex]y(t)=\dfrac{\sin t}{t^2}-\dfrac{\cos t}t+\dfrac C{t^2}[/tex]

Now use the initial condition to solve for C :

[tex]y\left(\dfrac\pi2\right)=9\implies9=\dfrac{\sin\frac\pi2}{\frac{\pi^2}4}-\dfrac{\cos\frac\pi2}{\frac\pi2}+\dfrac C{\frac{\pi^2}4}[/tex]

[tex]\implies9=\dfrac4{\pi^2}(1+C)[/tex]

[tex]\implies C=\dfrac{9\pi^2}4-1[/tex]

So the particular solution to the IVP is

[tex]y(t)=\dfrac{\sin t}{t^2}-\dfrac{\cos t}t+\dfrac{\frac{9\pi^2}4-1}{t^2}[/tex]

or

[tex]y(t)=\dfrac{4\sin t-4t\cos t+9\pi^2-4}{4t^2}[/tex]