Answer:
a = 8
b = -8
Step-by-step explanation:
You have the following function:
[tex]f(x)\\\\=at+b;\ \ t<2\\\\2t^2-1;\ \ 2\leq t[/tex]
A function is differentiable at a point c, if the derivative of the function in such a point exists. That is, f'(c) exists.
In this case, you need that the function is differentiable for t=2, then, you have:
[tex]f'(t)=a;\ \ \ \ t<2 \\\\f'(t)=4t;\ \ \ 2\leq t[/tex]
If the derivative exists for t=2, it is necessary that the previous derivatives are equal:
[tex]f'(2)=a=4(2)\\\\a=8[/tex]
Furthermore it is necessary that for t=2, both parts of the function are equal:
[tex]8(2)+b=2(2)^2-1\\\\16+b=8-1\\\\b=-8[/tex]
Then, a = 8, b = -8
Solve 2x^2 + x - 4 = 0
X2 +
Answer:
[tex]\large \boxed{\sf \ \ x = -\dfrac{\sqrt{33}+1}{4} \ \ or \ \ x = \dfrac{\sqrt{33}-1}{4} \ \ }[/tex]
Step-by-step explanation:
Hello, please find below my work.
[tex]2x^2+x-4=0\\\\\text{*** divide by 2 both sides ***}\\\\x^2+\dfrac{1}{2}x-2=0\\\\\text{*** complete the square ***}\\\\x^2+\dfrac{1}{2}x-2=(x+\dfrac{1}{4})^2-\dfrac{1^2}{4^2}-2=0\\\\\text{*** simplify ***}\\\\(x+\dfrac{1}{4})^2-\dfrac{1+16*2}{16}=(x+\dfrac{1}{4})^2-\dfrac{33}{16}=0[/tex]
[tex]\text{*** add } \dfrac{33}{16} \text{ to both sides ***}\\\\(x+\dfrac{1}{4})^2=\dfrac{33}{16}\\\\\text{**** take the root ***}\\\\x+\dfrac{1}{4}=\pm \dfrac{\sqrt{33}}{4}\\\\\text{*** subtract } \dfrac{1}{4} \text{ from both sides ***}\\\\x = -\dfrac{1}{4} -\dfrac{\sqrt{33}}{4} \ \ or \ \ x = -\dfrac{1}{4} +\dfrac{\sqrt{33}}{4}[/tex]
Hope this helps.
Do not hesitate if you need further explanation.
Thank you
"Radon: The Problem No One Wants to Face" is the title of an article appearing in Consumer Reports. Radon is a gas emitted from the ground that can collect in houses and buildings. At certain levels it can cause lung cancer. Radon concentrations are measured in picocuries per liter (pCi/L). A radon level of 4 pCi/L is considered "acceptable." Radon levels in a house vary from week to week. In one house, a sample of 8 weeks had the following readings for radon level (in pCi/L). 1.92.45.75.51.98.23.96.9 (a) Find the mean, median, and mode. (Round your answers to two decimal places.) mean 4.55 median 4.7 mode 1.9 (b) Find the sample standard deviation, coefficient of variation, and range. (Round your answers to two decimal places.) s CV % range (c) Based on the data, would you recommend radon mitigation in this house
Answer:
a) Mean = 4.55
Median = 4.7
Mode = 1.9
b) S = 2.3952
CV = 52.64 %
Range = 6.3
c) Yes, since the average and median values are both over "acceptable" ranges.
Step-by-step explanation:
Explanation is provided in the attached document.
A manufacturer claims that its rechargeable batteries are good for an average of more than 1.000 charges. A random sample of 100 batteries has a mean life of 1002 charges and a standard deviation of 14. Is there enough evidence to support this claim at a significance level of 0.01?
a. State the hypotheses.
b. State the test statistie information
c. State either the p-value or the critical information d. State your conclusion and explain your reasoning
It's 1000 charges and not 1.000 charges
Answer:
A)Null Hypothesis;H0: μ = 1000
Alternative Hypothesis;Ha: μ ≠ 1000
B) t-statistic = 1.4286
C) p-value = 0.15628
D) We conclude that we will fail to reject the manufacturers claim that its rechargeable batteries are good for an average of more than 1000 charges
Step-by-step explanation:
We are given;
x = 1002 charges
s = 14
μ = 1000 charges
n = 100
degree of freedom = n - 1 = 100 - 1 = 99
A) The hypotheses are;
Null Hypothesis;H0: μ = 1000
Alternative Hypothesis;Ha: μ ≠ 1000
B) t-statistic = (x - μ)/(s/√n)
(1002 - 1000)/(14/√100) = 1.4286
C) From the t-score calculator results attached, the p-value is approximately 0.15628
D) The P-value of 0.15628 is is greater than the significance level of 0.01, thus we fail to reject the null hypothesis, and we conclude that the result is statistically nonsignificant.
The perimeter of a rectangular field is 344m . If the width of the field is 75m, what is its length?
Answer:
97 m
Step-by-step explanation:
Perimeter = 2 * (length + width); perimeter = 344, width = 75 (solving for length)
344 = 2(length + 75)
172 = length + 75
length = 97
Based on the dot plot, which statements are correct? Check all that apply
Eleven students answered Mr. Chiu's question.
Twelve students answered Mr. Chiu's question.
Three people studied for two hours.
Three people studied for three hours.
Everyone who responded studied for at least one hour.
Four people studied for four or more hours
Answer: options 2,3and 6
Answer:
option
2-Twelve students answered Mr. Chiu’s question.
3-Three people studied for two hours.
6-Four people studied for four or more hours.
Step-by-step explanation:
hope this helps:)
A magazine provided results from a poll of 2000 adults who were asked to identify their favorite pie. Among the 2000 respondents, 11% chose chocolate pie, and the margin of error was given as plus or minus5 percentage points. What values do ModifyingAbove p with caret, ModifyingAbove q with caret, n, E, and p represent? If the confidence level is 95%, what is the value of alpha?
Answer:
[tex]\r p = 0.11[/tex]
[tex]\r q = 0.89[/tex]
n = 2000
[tex]E = \pm 5[/tex]
p - population proportion
[tex]\alpha = 5[/tex]%
Step-by-step explanation:
From the question we are told that
The sample size is [tex]n = 2000[/tex]
The proportion of the population for chocolate pie is [tex]p_c = 0.11[/tex]
The margin of error is [tex]E = \pm 5[/tex]%
Now in the question we are asked to provide the meaning of
[tex]\r p , \r q , n , E , and\ p[/tex]
Now [tex]\r p[/tex] is the sample proportion of the population that those chocolate pie as favorite pie of which is given from the question as 0.11
Now
[tex]\r q[/tex] is the sample proportion of the population that choose other pies apart from chocolate pie as their favorite and it is evaluated as
[tex]\r q = 1 - \r p[/tex]
[tex]\r q = 1 - 0.11[/tex]
[tex]\r q = 0.89[/tex]
n is the sample size which is given as n = 2000
E is the margin of error which given as [tex]E = \pm 5[/tex]%
p is the population proportion
Given that the confidence level is 95 % then the level of significance is mathematically evaluated as
[tex]\alpha =(100 - 95)[/tex]%
[tex]\alpha =[/tex]5%
6th grade math , help me please:)
Answer:
(a) $7/ticket
(b) 3 cats/dog
(c) 10 ft/sec
(d) 16 cups/gal
Step-by-step explanation:
(a) $35 for 5 tickets
$35/(5 tickets) = $7/ticket
(b) 21 cats and 7 dogs
21 cats/(7 dogs) = 3 cats/dog
(c) 40 ft in 4 seconds
40 ft/(4 sec) = 10 ft/sec
(d) 48 cups for 3 gallons
48 cups/(3 gal) = 16 cups/gal
P(x)=2x^5+9x^4+9x^3+3x^2+7x-6;x=i,-2
Answer:
The value of the polynomial function at P(1) and P(-2) is 24 and 0 respectively.
Step-by-step explanation:
We are given with the following polynomial function below;
[tex]\text{P}(x) = 2x^{5} +9x^{4} +9x^{3} +3x^{2}+7x-6[/tex]
Now, we have to calculate the value of P(x) at x = 1 and x = -2.
For this, we will substitute the value of x in the given polynomial and find it's value.
At x = 1;
[tex]\text{P}(1) = 2(1)^{5} +9(1)^{4} +9(1)^{3} +3(1)^{2}+7(1)-6[/tex]
[tex]\text{P}(1) = (2\times 1) +(9\times 1)+(9 \times 1)+(3\times 1)+(7\times 1)-6[/tex]
[tex]\text{P}(1) = 2 +9+9+3+7-6[/tex]
P(1) = 30 - 6
P(1) = 24
At x = -2;
[tex]\text{P}(-2) = 2(-2)^{5} +9(-2)^{4} +9(-2)^{3} +3(-2)^{2}+7(-2)-6[/tex]
[tex]\text{P}(-2) = (2\times -32) +(9\times 16)+(9 \times -8)+(3\times 4)+(7\times -2)-6[/tex]
[tex]\text{P}(-2) = -64 +144-72+12-14-6[/tex]
P(-2) = 156 - 156
P(-2) = 0
Hence, the value of the polynomial function at P(1) and P(-2) is 24 and 0 respectively.
A father's age is 4 times as that of his son's age. in 5 years time, the father will be 3 times as old as his son. what are their present ages?
Answer:
present age of son = 10 present age of father = 40Step-by-step explanation:
Let, present age of son be 'x'
present age of father be 'y'
y = 4x→ equation ( i )
After five years,
Son's age = x + 5
father's age = y + 5
According to Question,
[tex]y + 5 = 3(x + 5)[/tex]
Put the value of y from equation ( i )
[tex]4x + 5 = 3(x + 5)[/tex]
Distribute 3 through the parentheses
[tex]4x + 5 = 3x + 15[/tex]
Move variable to L.H.S and change it's sign
Similarly, Move constant to R.H.S. and change its sign
[tex]4x - 3x = 15 - 5[/tex]
Collect like terms
[tex]x = 15 - 5[/tex]
Calculate the difference
[tex]x = 10[/tex]
Now, put the value of X in equation ( i ) in order to find the present age of father
[tex]y = 4x[/tex]
plug the value of X
[tex] = 4 \times 10[/tex]
Calculate the product
[tex] = 40[/tex]
Therefore,
Present age of son = 10
present age of father = 40
Hope this helps..
Best regards!!
Which of the following shapes can NOT be created by revolving a two-dimensional figure around an axis? There can be more than 1. A. come B. cube C. Rectangular pyramid D. Rectangular Prism E. Cylinder F. Sphere
PLEASE HELP
Answer:
A. Cone
D. Rectangular Prism
E. Cylinder
F. Sphere
Step-by-step explanation:
Rectangular Prism is a solid three dimensional shape. It has six faces which are sides of a rectangle. It is also known as Cuboid. The rectangular prism cannot be formed with two dimensional shapes. Sphere is a geometrical object which is a three dimensional circle. This shape has a circumference so this shape cannot be formed with two dimensional shapes.
Determine which type of correlation is shown in the graphed relationship
Answer:
No correlation
Step-by-step explanation:
Hey there! :)
This has no correlation because all the points are spread out throughout the graph making no correlation.
Answer:
D no correlation
Step-by-step explanation:
too many scattered dot all over the place if its some going up down its NO CORRELATION!!!
The random variable x is the number of houses sold by a realtor in a single month at the Sendsom's Real Estate office. Its probability distribution is as follows:
Houses Sold (x) Probability P(x)
0 0.24
1 0.01
2 0.12
3 0.16
4 0.01
5 0.14
6 0.11
7 0.21
Find the mean of the given probability distribution.
A. μ = 3.35
B. μ = 3.50
C. μ = 3.60
D. μ = 3.40
Answer:
C. μ = 3.60
Step-by-step explanation:
Two tables have been attached to this response.
One of the tables contains the given data and distribution with two columns: Houses Sold and Probability
The other table contains the analysis of the data with additional columns: Frequency and Fx
=> The Frequency(F) column is derived from the product of the probability of each item in the Houses sold column and the total number of houses sold (which is 28). For example,
When the number of houses sold = 0
F = P(0) x Total number of houses sold
F = 0.24 x 28 = 6.72
When the number of houses sold = 1
F = P(1) x Total number of houses sold
F = 0.01 x 28 = 0.28
=> The Fx column is found by multiplying the Frequency column by the Houses Sold column. For example,
When the number of houses sold = 0
Fx = F * x
F = 6.72 x 0 = 0
Now to get the mean, μ we use the relation;
μ = ∑Fx / ∑F
Where;
∑Fx = summation of the items in the Fx column = 100.8
∑F = summation of the items in the Frequency column = 28
μ = 100.8 / 28
μ = 3.60
Therefore, the mean of the given probability distribution is 3.60
The mean of the discrete probability distribution is given by:
C. μ = 3.60
What is the mean of a discrete distribution?The expected value of a discrete distribution is given by the sum of each outcome multiplied by it's respective probability.
In this problem, the table x - P(x) gives each outcome and their respective probabilities, hence, the mean is:
[tex]E(X) = 0(0.24) + 1(0.01) + 2(0.12) + 3(0.16) + 4(0.01) + 5(0.14) + 6(0.11) + 7(0.21) = 3.6[/tex]
Hence option C is correct.
More can be learned about the mean of discrete distributions at https://brainly.com/question/24855677
The circumference of C is 72cm. What is the length of AB (the minor arc)
Answer:
Step-by-step explanation:
Can you please include a image?
Thanks!!!
Solve the following rational equation for x.
1/4x-3/4=7/x
Answer:
x1= -4, x2 = 7
Step-by-step explanation:
Move expression to the left-hand side:
1/4x-3/4-7/x=0
Write all the numerators above a common denominator:
x^2 - 3x - 28 /4x =0
When the quotient of expressions equal 0, the numerator has to be 0
x^2 + 4x - 7x - 28 = 0
x(x+4) - 7(x+4) =0
(x+4) × (x-7) =0
Separate into possible cases:
x+4=0
x-7=0
Answer: -9
Step-by-step explanation:
An ice sculpture is melting at a constant rate. It's weight changes -1 4/5 pounds every hour. What is the total change in weight of the sculpture after 3 1/2 hours?
Answer:
It will decrease by 6 3/10 lbs in the 3 1/2 hours
Step-by-step explanation:
The rate is -1 4/5 lbs per hour
The time is 3 1/2 hours
Multiply to find the weight change
-1 4/5 * 3 1/2
Change to improper fractions
- ( 5*1 +4) /5 * ( 2* 3+1)/2
- 9/5 * 7/2
-63/10
Changing back to a mixed number
-6 3/10
It will decrease by 6 3/10 lbs in the 3 1/2 hours
Answer:
-6 3/10 pounds
Step-by-step explanation:
The weight of ice sculpture changes -1 4/5 pounds every 1 hour.
In 3 1/2 hours, multiply the time with the weight.
-1 4/5 × 3 1/2
Multiply.
-9/5 × 7/2
-63/10 = -6 3/10
What is the range of the function f(x)=3/4|x|-3
Range is [tex]y\in[-3,+\infty)[/tex].
Hope this helps.
What is the value of the fourth term in a geometric sequence for which a1 =
30 and r= 1/2
Answer:
3¾
Step-by-step explanation:
Geometric sequence also known as geometric progression, can be said to be a sequence with a constant ratio between the terms.
Formula for geometric sequence:
[tex] a^n = a ( n-1 ) * r [/tex]
Given:
First term, a1 = 30
ratio, r = ½
Required:
Find the fourth term
Where, the first term, a¹ = 30
Second term: a² = 30 * ½ = 15
Third term: a³ = 15 * ½ = 7.5
Fourth term: a⁴ = 7.5 * ½ = 3.75 = 3¾
Therfore the fourth term of the geometric sequence is 3¾
Find the volume of the figure below. Round to the nearest tenth.
7 cm
7 cm
9 cm
20 cm
11 cm
Answer:
3057.6 cm³
Step-by-step explanation:
You have a cylinder and a rectangular prism. Solve for the area of each separately.
Cylinder
The formula for volume of a cylinder is V = πr²h. The radius is 7, and the height is 7.
V = πr²h
V = π(7)²(7)
V = π(49)(7)
V = 343π
V = 1077.57 cm³
Rectangular Prism
The formula for volume of a rectangular prism is V = lwh. The length is 20, the width is 11, and the height is 9.
V = lwh
V = (20)(11)(9)
V = (220)(9)
V = 1980 cm³
Add the areas of the two shapes.
1077.57 cm³ + 1980 cm³ = 3057.57 cm³
Round to the nearest tenth.
3057.57 cm³ ≈ 3057.6 cm³
solve for the inequality ᵏ⁄₄ ≥ 6
Answer:
k ≥ 24
Step-by-step explanation:
ᵏ⁄₄ ≥ 6
Multiply each side by 4
ᵏ⁄₄ *4 ≥ 6*4
k ≥ 24
Answer:
k≥24
Step-by-step explanation:
k/4≥6
Use the multiplication property of equality by multiplying both sides by 4 to get
k≥24
If this is wrong or if I did something wrong, please tell me so I can learn the proper way, I am just treating this like a normal problem
Thank you
Please answer in the form of a number
Answer:
d ≈ 8.3
Step-by-step explanation:
This is kind of like the pythagorean theorem, but with one extra value. Thus, [tex]d^2=l^2+w^2+h^2[/tex].
Plug in the values to get:
[tex]d^2=2^2+7^2+4^2\\d^2=4+49+16\\d^2=69\\d=\sqrt{69} \\[/tex]
Thus d ≈ 8.3
A 75 lb boy and a 65 lb girl play on a seesaw. The seesaw is 14 ft long and is pivoted exactly in the middle. If the girl sits on the end of her side, where must the boy sit to make the seesaw balance?
Answer: 6 feet from the pivot point
Step-by-step explanation:
Girl's weight x distance from center = Boy's weight x distance from center
65 (7) = 75x
[tex]\dfrac{65(7)}{75}=x[/tex]
6.066 = x
The boy needs to be placed 6 feet from the center (aka pivot point) which is the same as saying 1 foot from the end of the seesaw.
How many solutions does the following equation have? 14(z+3)=14z+21
Answer:
No solutions
Step-by-step explanation:
14(z + 3) = 14z + 21
Expand brackets.
14z + 42 = 14z + 21
Subtract 14z on both sides.
42 = 21
There are no solutions.
Answer:
No solution
Step-by-step explanation:
First, We have to simplify the right side.
Distribute 14, 14z+42.
Now the equation stands as 14z+42=14z+21
Subtract 14z from both sides,
this makes it 42=21.
We know when the solution is #=#, our answer is no solution.
less than 0 but greater than (−5)
Answer:
-5 < x < 0
Step-by-step explanation:
Find two numbers in a given ratio such that the difference of their squares is to the sum of the numbers in a given ratio.Ratios, respectively, are 3 to 1 and 6 to 1.
According to the given situation, the computation of two number in a given ratio is shown below:-
We assume the numbers is x and y
Given that
[tex]\frac{x}{y} = \frac{3}{1}[/tex]
x = 3y
and
[tex]\frac{x^2-y^2}{x + y} = \frac{6}{1} \\\\\frac{(x + y) (x - y)}{(x + y)} = 6[/tex]
With the help of above formula we will put the value and be able to find the values of x and y
x - y = 6
3y - y = 6
2y = 6
y = 3
x = 3y = 9
x = 9, y = 3
Therefore the correct answer is x = 9 where as y = 3
1. What are foci? 2. What is the first step to take to write the equation of a hyperbola? 3. How do you represent parts of a hyperbola algebraically?
Answer: see below
Step-by-step explanation:
1) Foci is plural for Focus. Since a hyperbola has two focus points, they are referred to as foci. The foci is where the sum of the distances from any point on the curve to the foci is constant.
2) When determining the equation of a hyperbola you need the following:
a) does the hyperbola open up or to the right?
b) what is the center (h, k) of the hyperbola?
c) What is the slope of the asymptotes of the hyperbola?
3) The equation of a hyperbola is:
[tex]\dfrac{(x-h)^2}{a^2}-\dfrac{(y-k)^2}{b^2}=1\qquad or\qquad \dfrac{(y-k)^2}{b^2}-\dfrac{(x-h)^2}{a^2}=1[/tex]
(h, k) is the center of the hyperbola± b/a is the slope of the line of the asymptotesThe equation starts with the "x" if it opens to the right and "y" if it opens upWHOEVER ANSWERS FIRST GETS BRAINLIEST:) Which expression represents the surface area of the cone? A cone with diameter 12 inches, height 8 inches, and slant height 10 inches. S A = pi r l + pi r squared (pi) (6) (10) + (pi) (6 squared) (pi) (8) (10) + (pi) (8 squared) (pi) (12) (10) + (pi) (12 squared) (pi) (10) (12) + (pi) (10 squared)
Answer:
Step-by-step explanation:
The surface area of a cone is:
● Sa = Pi*r^2 +Pi*r*l
r is the radius and l is the slant heigth
The diameter of this cone is 12 inches so the radius is 6 (12/2=6).
●Sa = Pi*36 +Pi*6*10
●Sa = 301.59 in^2
Answer:
pi (6) * 10+ pi ( 6)^2
Step-by-step explanation:
The surface area of a cone is given by
SA = pi rl +pi r^2 where r is the radius and l is the slant height
We know the diameter is 12 so the radius is 12/2 = 6
SA = pi (6) * 10+ pi ( 6)^2
calculate the value of angle A to one decimal place. Picture Attached
Answer:
[tex] A = 50.7 [/tex] (to nearest tenth)
Step-by-step explanation:
Use the Law of Cosines to find the value of angle A as follows:
[tex] cos(A) = \frac{b^2 + c^2 - a^2}{2*b*c} [/tex]
Where,
a = 7 in
b = 5 in
c = 9 in
Plug in the values into the formula
[tex] cos(A) = \frac{5^2 + 9^2 - 7^2}{2*5*9} [/tex]
[tex] cos(A) = \frac{57}{90} [/tex]
[tex] cos(A) = 0.6333 [/tex]
[tex] A = cos^{-1}(0.6333) [/tex]
[tex] A = 50.7 [/tex] (to nearest tenth)
A cash register has $10 and $50 dollars bills with total of $1080.there are 28 bills in total how many of each bills.
Hey there! I'm happy to help!
Let's set this up as a system of equations, where x is equal to the number of 10 dollar bills and y is equal to the number of 50 dollar bills.
10x+50y=1080
x+y=28
We want to solve for x or y. We can rearrange the second equation to find the value of one of the variables.
x+y=28
Subtract x from both sides.
y=28-x
Now, we have a value for y. So, we could replace the y in the first equation with 28-x and the solve for x.
10x+50(28-x)=1080
We use distributive property to undo the parentheses.
10x+1400-50x=1080
We combine like terms.
-40x+1400=1080
We subtract 1400 from both sides.
-40x=-320
We divide both sides by -40.
x=8
Since there are 28 total bills, this means that there must be 20 50 dollar ones because there are 8 10 dollar bills.
Have a wonderful day! :D
What is the focus of the parabola? y=−1/4x2−x+3
Answer: Focus = (-2, 3)
Step-by-step explanation:
[tex]y=-\dfrac{1}{4}x^2-x+3\\\\\rightarrow a=-\dfrac{1}{4},\ b=-1[/tex]
First let's find the vertex. We do that by finding the Axis-Of-Symmetry:
[tex]AOS: x=\dfrac{-b}{2a}\quad =\dfrac{-(-1)}{2(\frac{-1}{4})}=\dfrac{1}{-\frac{1}{2}}=-2[/tex]
Then finding the maximum by inputting x = -2 into the given equation:
[tex]y=-\dfrac{1}{4}(-2)^2-(-2)+3\\\\y=-1+2+3\\\\y=4[/tex]
The vertex is: (-2, 4)
Now let's find p, which is the distance from the vertex to the focus:
[tex]a=\dfrac{1}{4p}\\\\\\-\dfrac{1}{4}=\dfrac{1}{4p}\\\\\\p=-1[/tex]
The vertex is (-2, 4) and p = -1
The focus is (-2, 4 + p) = (-2, 4 - 1) = (-2, 3)
Find the perimeter of an equilateral triangle where area is 72cm.
Answer:
38.68 cm
Step-by-step explanation:
Perimeter of an equilateral triangle : P = 3a
Area of an equilateral triangle : A = [tex]\frac{\sqrt{3} }{4}a^2[/tex]
a = side length
The area is given, solve for a.
[tex]72= \frac{\sqrt{3} }{4}a^2[/tex]
[tex]a = 12.894839[/tex]
The side length is 12.894839 centimeters.
Find the perimeter.
P = 3a
P = 3(12.894839)
P = 38.684517 ≈ 38.68
The perimeter is 38.68 centimeters.