Given function [tex]f(x)=x^2-4[/tex] find its inverse by substituting x for f(x) and then solving for f(x).
[tex]x=f(x)^2-4\implies f(x)^{-1}=\sqrt{x+4}[/tex]
Where [tex]x+4>=0[/tex] for x to be real.
So solve the inequality and you will obtain the domain:
[tex]x+4>=0\implies x>=-4\implies x\in[-4,+\infty)[/tex].
Range is equal to the range of square root function,
[tex]y\in[0, +\infty)[/tex].
Hope this helps.
No need of a answer anymore.
Answer:
mean score of class B = 1778/25 = 71.12
Step-by-step explanation:
This was your question : Class A has 12 pupils and class B has 25 pupils. Both classes sit the same maths test. The mean score for class A is 80. The mean score for both classes is 74. What is the mean score (rounded to 2 DP) in the maths test for class B?
mean of class A = Σfx/Σf
mean of class A = 80
Σfx = 80 × 12 = 960
Mean score for both classes = 74
where
b = Σfx of class B
960 + b/37 = 74
cross multiply
960 + b = 2738
b = 2738 - 960
b = 1778
mean score of class B = Σfx/Σf
Σfx = 1778
Σf = 25
Therefore,
1778/25 = 71.12
Segu
Find a formula for the nth term in this
arithmetic sequence:
a1 = 7, a2 = 4, a3 = 1, a4 = -2, ...
Answer:
The formula is 10 - 3n
Step-by-step explanation:
For an nth term in an arithmetic sequence
U( n ) = a + ( n - 1)d
Where n is the number of terms
a is the first term
d is the common difference
From the sequence above
a = 7
d = 4 - 7 = - 3
The formula for an nth term is
U(n) = 7 + (n - 1)-3
= 7 - 3n + 3
The final answer is
= 10 - 3n
Hope this helps you.
A jar of sweet contains 5 yellow sweets, 4 red sweets, 8 green sweets, 4 orange sweets and 3 white sweets. Ola chose a sweet at random, what is the possibility that she will pick either a yellow or orange sweet?
Answer:
9/24 or 37.5%
hope this helps :)
Hi,
first thing you must do with a probability problem is to count how many thing you have in your universe.
Here we are dealing with sweets. So let's count : 5 +4+8+4+3 = 24
and there is 5 yellow so probability to pick up a yellow is 5/24
and there is 4 orange so probabilitu to pick up a orange is 4/24
To say : Ola will pick orange or yellow mean if she pick either one of the two sort is good. So you add the proba of each : 5/24 +4/24 = 9/24
and then you must reduce if you can : 9/24 = 3*3 /8*3 = 3/8
So the probability that Ola pick a yellow or orange sweet is 3/8 = 0.375
The ratio of sides of 2 similar cubes is 3:4. Larger cube has a volume of 1728 cubic meters. What is the volume of the smaller cube?
Answer:
See steps
Step-by-step explanation:
Volume of cubes is proportional to the cube of the side length.
Using proportions,
Volume of smaller cube / 1728 = (3/4)^3
Cross multiply,
Volume of smaller cube
= 1728 * (3/4)^3
= 1728 * (27/64)
= 729 cubic metres.
Note: all cubes are similar and each has 6 congruent faces.
Write the limit as a definite integral on the interval [a, b], where ci is any point in the ith subinterval. Limit Interval lim ||Δ|| → 0 n (4ci + 11) i = 1 Δxi [−8, 6]
Answer:
The corresponding definite integral may be written as
[tex]\int_a^b \mathrm{(4x + 11)}\,\mathrm{d}x[/tex]
The answer of the above definite integral is
[tex]\int_a^b \mathrm{(4x + 11)}\,\mathrm{d}x = 98[/tex]
Step-by-step explanation:
The given limit interval is
[tex]\lim_{||\Delta|| \to 0} \sum\limits_{i=1}^n (4c_i + 11) \Delta x_i[/tex]
[tex][a, b] = [-8, 6][/tex]
The corresponding definite integral may be written as
[tex]\int_a^b \mathrm{(4x + 11)}\,\mathrm{d}x[/tex]
[tex]\int_{-8}^6 \mathrm{(4x + 11)}\,\mathrm{d}x[/tex]
Bonus:
The definite integral may be solved as
[tex]\int_{-8}^6 \mathrm{(4x + 11)}\,\mathrm{d}x \\\\\frac{4x^2}{2} + 11x \left \|{b=6} \atop {a=-8}} \right. \\\\2x^2 + 11x \left \|{b=6} \atop {a=-8}} \right. \\\\ 2(6^2 -(-8)^2 ) + 11(6 - (-8) \\\\2(36 - 64 ) + 11(6 + 8) \\\\2(-28 ) + 11(14) \\\\-56 +154 \\\\98[/tex]
Therefore, the answer to the integral is
[tex]\int_a^b \mathrm{(4x + 11)}\,\mathrm{d}x = 98[/tex]
Exercise 9
The bedroom is similar to the bed. Find the perimeter of the bedroom to the nearest foot
Bedroom
7 ft
16 ft
15 ft
Answer:
56 ft
Step-by-step explanation:
Because the bedroom is similar to the bed we can write that
7 : 15 = 6 : x
x = 15*6/7 ≈ 12.86 ft
Perimeter of the bedroom is
15*2 + 12.86 *2 ≈ 56 ft
Use the substitution x = et to transform the given Cauchy-Euler equation to a differential equation with constant coefficients. Solve the original equation by solving the new equation
x2y'' + 9xy' - 20y = 0
Answer:
[tex]\boxed{\sf \ \ \ ax^2+bx^{-10} \ \ \ }[/tex]
Step-by-step explanation:
Hello,
let's follow the advise and proceed with the substitution
first estimate y'(x) and y''(x) in function of y'(t), y''(t) and t
[tex]x(t)=e^t\\\dfrac{dx}{dt}=e^t\\y'(t)=\dfrac{dy}{dt}=\dfrac{dy}{dx}\dfrac{dx}{dt}=e^ty'(x)<=>y'(x)=e^{-t}y'(t)\\y''(x)=\dfrac{d^2y}{dx^2}=\dfrac{d}{dx}(e^{-t}\dfrac{dy}{dt})=-e^{-t}\dfrac{dt}{dx}\dfrac{dy}{dt}+e^{-t}\dfrac{d}{dx}(\dfrac{dy}{dt})\\=-e^{-t}e^{-t}\dfrac{dy}{dt}+e^{-t}\dfrac{d^2y}{dt^2}\dfrac{dt}{dx}=-e^{-2t}\dfrac{dy}{dt}+e^{-t}\dfrac{d^2y}{dt^2}e^{-t}\\=e^{-2t}(\dfrac{d^2y}{dt^2}-\dfrac{dy}{dt})[/tex]
Now we can substitute in the equation
[tex]x^2y''(x)+9xy'(x)-20y(x)=0\\<=> e^{2t}[ \ e^{-2t}(\dfrac{d^2y}{dt^2}-\dfrac{dy}{dt}) \ ] + 9e^t [ \ e^{-t}\dfrac{dy}{dt} \ ] -20y=0\\<=> \dfrac{d^2y}{dt^2}-\dfrac{dy}{dt}+ 9\dfrac{dy}{dt}-20y=0\\<=> \dfrac{d^2y}{dt^2}+ 8\dfrac{dy}{dt}-20y=0\\[/tex]
so the new equation is
[tex]y''(t)+ 8y'(t)-20y(t)=0[/tex]
the auxiliary equation is
[tex]x^2+8x-20=0\\<=> x^2-2x+10x-20=0\\<=>x(x-2)+10(x-2)=0\\<=>(x+10)(x-2)=0\\<=> x=-10\text{ or }x=2[/tex]
so the solutions of the new equation are
[tex]y(t)=ae^{2t}+be^{-10t}[/tex]
with a and b real
as
[tex]x(t)=e^t\\<=> t(x)=ln(x)[/tex]
[tex]y(x)=ae^{2ln(x)}+be^{-10ln(x)}=ax^2+bx^{-10}[/tex]
hope this helps
do not hesitate if you have any questions
Solve the equation. y + 3 = –y + 9
A. y = 1
B. y = 3
C. y = 6
D. y = 9
Answer:
y=3
Step-by-step explanation:
y + 3 = –y + 9
Add y to each side
y+y + 3 = –y+y + 9
2y+3 = 9
Subtract 3 from each side
2y+3-3 = 9-3
2y = 6
Divide by 2
2y/2 = 6/3
y =3
Answer:
Hello!
_______________________
Your answer would be (B) y = 3
Step-by-step explanation: Isolate the variable by dividing each side by factors that don't contain the variable.
Hope this helped you!
Express it in slope-Intercept form
Answer:
Y=1/4x-4
Explanation: The y intercept is -4 that is your B. Using the rise over sun method the line rises 1 and goes to the right 4 making the slope 1/4 or .25
Bob bought some land costing $15,540. Today, that same land is valued at $45,117. How long has Bob owned this land if the price of land has been increasing at 5 percent per year
Answer:
21.84 years
Step-by-step explanation:
From the compound interest formula;
F = P(1+r)^t .......1
ln(F/P) = tln(1+r)
t = ln(F/P)/ln(1+r) .......2
Where;
F = Final value = $45,117
P = Initial value = $15,540
r = rate = 5% = 0.05
t = time
Substituting the values into equation 2;
t = ln(45117/15540)/ln(1.05)
t = 21.84542292124 years
t = 21.84 years
It will take Bob 21.84 years
Evaluate: .25 (1.2 x 3 - 1.25) + 3.45
The order to us solve is:
ParenthesesMultiplicationSum and subtractionLet's go:
[tex]25(1.2\times 3 - 1.25) + 3.45\\25(3.6-1.25)+3.45\\25\times 2.35 + 3.45\\58.75+3.45\\62.2[/tex]
Therefore, the result is 62.2.
Answer:
4.0375
Step-by-step explanation:
.25(3.6-1.25)+3.45
.25(2.35)+3.45
.5875+3.45
4.0375
HOPE THIS HELPS:)
The tread life of a particular brand of tire is a random variable best described by a normal distribution with a mean of 60,000 miles and a standard deviation of 1100 miles. What warranty should the company use if they want 96% of the tires to outlast the warranty? Round the answer to the nearest whole number
Answer:
61,925 miles
Step-by-step explanation:
Given :
The p-value of the tires to outlast the were warranty were given in the the question as = 0.96
Checking the normal distribution table, The probability that corresponds to 0.96
from the Normal distribution table is 1.75.
Mean : 'μ'= 60000 miles
Standard deviation : σ=1100
The formula for z-score is given by
: z= (x-μ)/σ
1.75=(x-60000)/1100
1925=x-60000
x=61925
Therefore, the tread life of tire should be 61,925 miles if they want 96% of the tires to outlast the warranty.
Richard has enrolled in a 401(k) savings plan. He intends to deposit $250 each month; his employer does not contribute to his account. How much will be in his account in 20 years?
Answer:
Richard will have $60,000 in his account in 20 years.
Step-by-step explanation:
(1) Multiply $250 x 12
(2) Multiply the answer of $250 x 12 which is 3000 by 20
(3) Final answer would be $60,000
In a test of the effectiveness of garlic for lowering cholesterol, 47 subjects were treated with garlic in a processed tablet form. Cholesterol levels were measured before and after the treatment. The changes (beforeminusafter) in their levels of LDL cholesterol (in mg/dL) have a mean of 2.7 and a standard deviation of 17.8. Construct a 90% confidence interval estimate of the mean net change in LDL cholesterol after the garlic treatment. What does the confidence interval suggest about the effectiveness of garlic in reducing LDL cholesterol?
The 90% confidence interval for the mean net change in LDL cholesterol after the garlic treatment is approximately -1.799 to 7.199, suggesting that the effectiveness of garlic in reducing LDL cholesterol is not statistically significant.
We have,
To construct a 90% confidence interval estimate of the mean net change in LDL cholesterol after the garlic treatment, we can use the formula:
CI = X ± (Z * (σ/√n))
where:
CI is the confidence interval
X is the sample mean
Z is the critical value corresponding to the desired confidence level (90% confidence level corresponds to Z = 1.645 for a large sample size)
σ is the population standard deviation
n is the sample size
Given that the sample mean X of the net change in LDL cholesterol is 2.7, the standard deviation (σ) is 17.8, and the sample size (n) is 47, we can calculate the confidence interval as follows:
CI = 2.7 ± (1.645 * (17.8/√47))
Calculating the standard error (SE):
SE = σ/√n = 17.8/√47 ≈ 2.587
Substituting the values into the confidence interval formula:
CI = 2.7 ± (1.645 * 2.587)
Calculating the upper and lower bounds of the confidence interval:
Upper bound = 2.7 + (1.645 * 2.587) ≈ 7.199
Lower bound = 2.7 - (1.645 * 2.587) ≈ -1.799
Therefore, the 90% confidence interval estimate for the mean net change in LDL cholesterol after the garlic treatment is approximately -1.799 to 7.199.
Interpreting the confidence interval:
Since the confidence interval contains both positive and negative values, it suggests that the effectiveness of garlic in reducing LDL cholesterol is not statistically significant.
The interval includes zero, indicating that there is a possibility that the mean net change in LDL cholesterol after the garlic treatment could be zero (no change).
However, it is important to note that further studies or a larger sample size may be needed to draw more definitive conclusions.
Thus,
The 90% confidence interval for the mean net change in LDL cholesterol after the garlic treatment is approximately -1.799 to 7.199, suggesting that the effectiveness of garlic in reducing LDL cholesterol is not statistically significant.
Learn more about confidence intervals here:
https://brainly.com/question/32546207
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The 90% confidence interval suggests that the true mean net change in LDL cholesterol after the garlic treatment lies between -1.57 and 6.97 mg/dL. Since the interval contains both positive and negative values, it indicates that the garlic treatment may or may not be effective in reducing LDL cholesterol.
What does the confidence interval suggest about the effectiveness of garlic in reducing LDL cholesterol?To construct a 90% confidence interval estimate of the mean net change in LDL cholesterol after the garlic treatment, we can use the formula:
CI = mean ± (Z * (standard deviation / √n))
Here, n represents the sample size (47), Z is the critical value corresponding to a 90% confidence level (Z = 1.645 for a 90% confidence level), and the mean is 2.7 with a standard deviation of 17.8.
Plugging in the values:
CI = 2.7 ± (1.645 * (17.8 / √47))
CI = 2.7 ± (1.645 * (17.8 / 6.856))
CI = 2.7 ± (1.645 * (2.596))
CI = 2.7 ± 4.270
CI = 2.7 + 4.270 ; CI = 2.7 - 4.270
CI = 6.97 ; CI = -1.57
Thus, the 90% confidence interval estimate for the mean net change in LDL cholesterol after the garlic treatment is approximately (-1.57, 6.97).
The confidence interval suggests that the effectiveness of garlic in reducing LDL cholesterol is inconclusive. The interval spans both positive and negative values, indicating that the true mean change in LDL cholesterol could be anywhere within this range. Further research or a larger sample size might be needed to draw a more definitive conclusion about the effectiveness of garlic in lowering LDL cholesterol.
Read more about confidence interval here: https://brainly.com/question/20309162
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pls help help help help
Answer:
D
Step-by-step explanation:
We can plug in the numbers (15, 23, 25, 38, 53) into the equation for x, and see if we get the values given for the number of hits (4, 12, 14, 27, 47)
What is an equation in point-slope form for the line that passes through the points (4,−1) and (−3,4)? y+4=−57(x+3) y+4=57(x+3) y−4=−57(x+3) y−3=−57(x+4) PLEASE HELP MEEEE
Answer:
Step-by-step explanation:
(4+1)/(-3-4)= -5/7
y + 1 = -5/7(x - 4)
or
y - 4= -5/7(x + 3)
Rewrite 19/3 as a mixed number
Answer:
[tex]6\frac{1}{3}[/tex]
Step-by-step explanation:
You can divide 19 by 3 a total of 6 times with a remainder of 1.
Elliot’s school has 24 classrooms. Each classroom has seats for 26 students. What is the maximum number of students the school can seat? Multiply to find the answer.
Answer:
24*26= 624 students
hope this helps!
Answer:
624 seats
Step-by-step explanation:
Total classrooms = 24
Each classroom has seats = 26
Total Number of seats = 24*26
=> 624 seats
Please help me it’s due tomorrow and I really need help
Answer:
5 [tex]\frac{1}{3}[/tex], 10 [tex]\frac{2}{3}[/tex]
Step-by-step explanation:
There is a common ratio r between consecutive terms, that is
[tex]\frac{2}{3}[/tex] ÷ [tex]\frac{1}{3}[/tex] = 1 [tex]\frac{1}{3}[/tex] ÷ [tex]\frac{2}{3}[/tex] = 2 [tex]\frac{2}{3}[/tex] ÷ 1 [tex]\frac{1}{3}[/tex] = 2
Thus to obtain a term in the sequence multiply the previous term by 2, thus
a₅ = [tex]\frac{8}{3}[/tex] × 2 = [tex]\frac{16}{3}[/tex] = 5 [tex]\frac{1}{3}[/tex]
a₆ = [tex]\frac{16}{3}[/tex] × 2 = [tex]\frac{32}{3}[/tex] = 10 [tex]\frac{2}{3}[/tex]
Equations and functions
What’s the answer to this ? I’m haveing trouble
Answer:
B / px= k
Step-by-step explanation:
B = kpx
Divide each side by px
B / px= kpx/px
B / px= k
Answer:
First option
Step-by-step explanation:
B=kpx
B=k*(px)
Then,
[tex]k = \frac{b}{px} [/tex]
Jackie built a fence around her garden to keep animals out. The dimensions of the area enclosed by
the fence are shown in the diagram below. What is
the total area, in square feet, enclosed by the fence?
Answer:
the second one
Step-by-step explanation:
We can see that the fence is made by a rectangle and a trapezoid
A1 is the area of the rectangle and A2 is the area of the trapezoid
A1 = 9*12A2= [(1/2)*(18+12)*6)) by adding them we get the second oneA rectangular box has length 2 inches, width 8 inches, and a height of 10 inches. Find the angle between the diagonal of the box and the diagonal of its base. The angle should be measured in radians.
Answer:
a) diagonal box = 12.9 in
b) diagonal base = 8.2 in
Step-by-step explanation:
w = 8 in
h = 10 in
L = 2 in
required:
a) diagonal of the box
b) diagonal of its base
referring into the attached image
a) the diagonal of the box = sqrt ( w² + h² + L²)
diagonal box = sqrt (8² + 10² + 2²)
diagonal box = 12.9 in
b) diagonal of its base = sqrt ( w² + L²)
diagonal base = sqrt ( 8² + 2²)
diagonal base = 8.2 in
All cell phone plans from Mobile USA require an additional $10/month data fee on top of the base plan price.
Lindsay has the $39.99/month base cell phone plan from MobileUSA.
Conjecture: Lindsay pays at least $49.99/month for her cell phone.
Use deductive reasoning to verify the conjecture, or provide a counterexample if the conjecture is false.
A true, law of detachment
В. false, Lindsay does not have a data fee
С. false, Lindsay is not a Mobile USA customer
Dfalse, not all MobileUSA customers have a data fee
Answer:
A
Step-by-step explanation:
Answer:
A True, law of detachment.
which is bigger 1 or
[tex] \frac{19}{9} [/tex]
Answer:
19/9 because it equals to 2.111.. Which is greater than 1
Step-by-step explanation:
By the way if it's right can i get brainliest.
Answer:
1 < 19/9
Step-by-step explanation:
1 vs 19/9
Rewriting 19/9 as 9/9 + 9/9+ 1/9
1 vs 1+1 +1/9
1 vs 2 1/9
1 < 19/9
Domain and range of T
Answer:
Let's list out the points that belong to T. They are T{(-1, -4), (2, 2), (2, -3)}.
The domain is all of the x values. Therefore the domain is {-1, 2}.
The range is all of the y values. Therefore the range is {-4, -3, 2}.
We don't use ( ) or [ ] because T is a discrete relation.
Rationalize the denominator and simplify
Answer:
sqrt(70)/7
Step-by-step explanation:
sqrt(10/7)
sqrt ( a/b) = sqrt(a)/ sqrt(b)
sqrt(10) / sqrt(7)
But we don't leave a sqrt in the denominator, so multiply by sqrt(7) /sqrt(7)
sqrt(10) /sqrt(7) * sqrt(7) / sqrt(7)
sqrt(70)/ sqrt(49)
sqrt(70)/7
The length of a rectangle is 11 yds more than twice the width, and the area of the rectangle is 63 yd ^2, find the dimentions of the rectangle
Answer:
The length is 18 ydThe width is 3.5 ydStep-by-step explanation:
Area of a rectangle = l × w
where l is the length
w is the width
length of a rectangle is 11 yds more than twice the width is written as
l = 11 + 2w
Area = 63 yd²
(11+2w)w = 63
2w² + 11w - 63 = 0
Solve the quadratic equation
( w + 9) ( 2x - 7) = 0
w = - 9 w = 7/2 or 3.5
Since width is always positive w is 3.5 yd
l = 11 + 2(3.5)
l = 11 + 7
l = 18 yd
The length is 18 yd
The length is 18 ydThe width is 3.5 yd
Hope this helps you
Tickets to a baseball game can be ordered online for a set price per ticket plus a $5.59 service fee. The total cost in dollars for ordering 5 tickets is $108.09. Which linear function represents c, the total cost, when x tickets are ordered
Answer:
c = 20.5x + 5.59
Step-by-step explanation:
c = mx + b
c = mx + 5.59
108.09 = m(5) + 5.59
5m = 102.5
m = 20.5
c = 20.5x + 5.59
Keisha wants to estimate the percentage of managers at her company that hold an MBA. She surveys 320 managers and finds that 70 hold an MBA. Find the margin of error for the confidence interval for the population proportion with a 90% confidence level.
Answer:
The margin of error is of 0.038 = 3.8%.
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of [tex]\pi[/tex], and a confidence level of [tex]1-\alpha[/tex], we have the following confidence interval of proportions.
[tex]\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]
In which
z is the zscore that has a pvalue of [tex]1 - \frac{\alpha}{2}[/tex].
For this problem, we have that:
[tex]n = 320, \pi = \frac{70}{320} = 0.21875[/tex]
90% confidence level
So [tex]\alpha = 0.1[/tex], z is the value of Z that has a pvalue of [tex]1 - \frac{0.1}{2} = 0.95[/tex], so [tex]Z = 1.645[/tex].
The margin of error is:
[tex]M = z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]
[tex]M = 1.645\sqrt{\frac{0.21875(1-0.21875)}{320}}[/tex]
[tex]M = 0.038[/tex]
The margin of error is of 0.038 = 3.8%.
someone help me out pls
Answer:
EF ≈ 3.8
Step-by-step explanation:
Using the Sine rule in Δ DEF
[tex]\frac{EF}{sin75}[/tex] = [tex]\frac{DE}{sin50}[/tex] , that is
[tex]\frac{EF}{sin75}[/tex] = [tex]\frac{3}{sin50}[/tex] ( cross- multiply )
EF × sin50° = 3 × sin75° ( divide both sides by sin50° )
EF = [tex]\frac{3sin75}{sin50}[/tex] ≈ 3.8