When a circular plate of metal is heated in an oven, its radius increases at a rate of 0.02 cm divided by min0.02 cm/min. at what rate is the plate's area increasing when the radius is 4040 cm?
Since the plate is circular, therefore the area of the plate is jut equal to the area of a circle, so:
Area of plate = πr² = A
Taking the derivative:
dA / dr = 2πr --->
1
By
the idea of partial differentiation, the equation can also take in the form of:
dA/dt = dA/dr x dr/dt ---> 2
Where
we are given that:
change in radius over time = dr/dt = 0.02 cm/min
change in area with changing radius = dA/dr = 2πr ---> from equation 1
at r = 40
dA/dr = 2π(40) = 80π
Substituting
all the known values into equation 2:
dA/dt = (80π)(0.02)
dA/dt = 1.6π cm^2 /s = 5.03 cm^2/s
The length of a screw produced by a machine is normally distributed with a mean of 0.65 inches and a standard deviation of 0.01 inches. What percent of screws are between 0.61 and 0.69 inches?
HELP
A. 65%
B. 68%
C. 99.7%
D. 99.9936%
Answer:
D. 99.9936%.
Step-by-step explanation:
We have been given that the length of a screw produced by a machine is normally distributed with a mean of 0.65 inches and a standard deviation of 0.01 inches.
To find the percent of screws that are between 0.61 and 0.69 inches, first of we will find z-score for our given raw scores using z-score formula.
[tex]z=\frac{x-\mu}{\sigma}[/tex], where,
[tex]z=\text{z-score}[/tex],
[tex]x=\text{Raw-score}[/tex],
[tex]\mu=\text{Mean}[/tex],
[tex]\sigma=\text{Standard deviation}[/tex].
Now let us find z-score corresponding to our given raw scores.
[tex]z=\frac{0.61-0.65}{0.01}[/tex]
[tex]z=\frac{-0.04}{0.01}[/tex]
[tex]z=-4[/tex]
Now let us find z-score for raw score 0.69.
[tex]z=\frac{0.69-0.65}{0.01}[/tex]
[tex]z=\frac{0.04}{0.01}[/tex]
[tex]z=4[/tex]
Now we will use formula to find the probability between two z-score as:
[tex]P(a<z<b)=P(z<b)-P(z<a)[/tex]
Upon substituting our given values in above formula we will get,
[tex]P(-4<z<4)=P(z<4)-P(z<-4)[/tex]
Using normal distribution table we will get,
[tex]P(-4<z<4)=0.99997-0.00003[/tex]
[tex]P(-4<z<4)=0.99994[/tex]
Now let us convert our answer into percent by multiplying 0.99994 by 100.
[tex]0.99994\times 100=99.994\%[/tex]
Therefore, 99.994% of screws are between 0.61 and 0.69 inches and option D is the correct choice.
Solve for x.5(x – 10) = 30 – 15x
Answer:
x=4
Step-by-step explanation:
Identify the slope of the line shown in the graph below:
A bridge builder wants to know the width of a river. He stands at point A along the river. He picks a point C directly across the river. He then walks downstream 90 feet from point A to point B. From point B, he sites C and determines the angle between the bank and point C (θ), to be 43º. What is the width of the river?
The bridge builder used the tangent function to calculate the width of the river. The equation tan(43) = width/90 was set up, and solving for width gives an answer of approximately 91.6 feet.
Explanation:The question gives us a right triangle set up, where point A is where the builder starts, point B is where he walks to, and point C is directly across the river. We can use trigonometry, specifically the tangent function, to find the unknown side. In a right triangle, the tangent of an angle is equal to the ratio of the opposite side (the side across from the angle) to the adjacent side (the side next to the angle).
The angle (θ) in this case is 43 degrees, the side adjacent to the angle is the walk of 90 feet, and the side opposite the angle is the width of the river, which we'll call 'w'. So we get the equation: tan(43) = w/90. Solving for 'w' gives us the width of the river.
Therefore, w = 90 * tan(43), which calculates to approximately 91.6 feet. So the width of the river is approximately 91.6 feet.
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what is the coefficient of x^2y^3 in the expansion of (2x+y)^5
Answer:
The coefficient of x²y³ is 40.
Step-by-step explanation:
The binomial expansion is defined as
[tex](a+b)^n=^nC_0a^n+^nC_1a^{n-1}b+...+^nC_ra^rb^{n-r}+....+^nC_nb^n[/tex]
The expression is
[tex](2x+y)^5[/tex]
Expand the binomial expansion.
[tex](2x+y)^5=^5C_0(2x)^5+^5C_1(2x)^{4}(y)+^5C_2(2x)^{3}(y)^2+^5C_3(2x)^{2}(y)^3+^5C_4(2x)^{1}(y)^4+^5C_5(y)^5[/tex]
Combination formula:
[tex]^nC_r=\frac{n!}{r!(n-r)!}[/tex]
[tex](2x+y)^5=32 x^5 + 80 x^4 y + 80 x^3 y^2 + 40 x^2 y^3 + 10 x y^4 + y^5[/tex]
Therefore the coefficient of x²y³ is 40.
Answer:40
Step-by-step explanation:
algebra 2 test
When is buying a house and renting it out a profitable venture?
Answer:
When what you enter for rent is greater than the mortgage, taxes, maintenance and rent.
Step-by-step explanation:
Buying the house is an investment if we do it to generate income. Otherwise, it is simply the place where we live, spend time and enjoy with our family
The purchase for investment purposes is when we buy apartments for rent or for the purpose of renovating and selling them quickly for a higher price.
We know that y=mx+b is the formula we use for lines. Is the value of "m" considered to be a term, a coefficient or a factor?
Question 3 options:
Term
Coefficient
Factor
Hey 5ever can u solve dis please.
Factor:
(3x+5xy)^2
Need help. Have photo
which decimal is closest in value to the fraction below 1/9 ?
a) 0.111
b) .33333
c) 0.7
Find all solutions to the equation. (sin x)(cos x) = 0
To solve the equation (sin x)(cos x) = 0, we find that sin x equals zero when x is an integral multiple of π , while cos x equals zero at odd multiples of π/2 . Therefore, our solutions are x = nπ and x = (2n + 1)π/2 for any integer n.
To find all solutions to the equation (sin x)(cos x) = 0, we need to identify the values of x at which either sin x = 0 or cos x = 0, because if either factor on the left-hand side is zero, the product will be zero.
For sin x = 0, the solutions are where x is an integral multiple of π . This can be written as x = nπ, where n is any integer (..., -3, -2, -1, 0, 1, 2, 3, ...).
For cos x = 0, the solutions occur at odd multiples of π/2. Therefore, the solutions can be represented as x = (2n + 1)π/2, where n is any integer.
Combining both sets of solutions, we have x = nπ and x = (2n + 1)π/2, for n being any integer.
In your lease agreement you are allowed 25000 km per year for free. After that you are charged $0.08 per km. After yoir 5 year term, you drove a total of 140000 km. How much do you owe?
After 5 year term, the distance covered is 140000 km, the charge paid is, $1200
What is multiplication?The fundamental concept of repeatedly adding the same number is represented by the process of multiplication. The results of multiplying two or more numbers are known as the product of those numbers, and the components that are multiplied are referred to as the factors.
Given that,
In lease agreement, the distance allowed 25000 km per year for free
After that the charge will be $0.08 per km
After 5 year term, you drove a total of 140000 km
The owed amount = ?
So, in 5 year term the distance which is free according to agreement,
⇒ 5 × 25000
⇒ 125000
Now, the distance for which charge has given
⇒ 140000 - 125000
⇒ 15000
Charged amount = $0.08 per km
The owed amount = 0.08 × 15000
= $1200
Hence, the amount owed is $1200
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If pentagon OPQRS is dilated by a scale factor of seven over four from the origin, to create O'P'Q'R'S', what is the ordered pair of point P'?
If a binomial event has a probability of success of 0.2, how many successes would you expect out of 6000 trials?
Answer:
The success would expect are 1200.
Step-by-step explanation:
Given : If a binomial event has a probability of success of 0.2.
To find : How many successes would you expect out of 6000 trials?
Solution :
The probability of success p=0.2.
The number of trials is n=6000
The formula to find number of successes is
The mean (expected value) of number of successes is the multiple of success and number of trials,
[tex]M=np[/tex]
[tex]M=6000\times 0.2[/tex]
[tex]M=1200[/tex]
Therefore, The success would expect are 1200.
Given f(x) = x2 + x − 2 and g(x) = 2x − 4, identify (f + g)(x).
The sum of two numbers is 64 . the smaller number is 14 less than the larger number. what are the numbers?
The value of a larger number is 39 and the smaller number is 25.
Given that,
The sum of the two numbers is 64.
And, the smaller number is 14 less than the larger number.
Let us assume that,
The larger number is = x
Then, the value of smaller numbers = x - 14
Since the sum of the two numbers is 64.
Hence we get;
x + (x - 14) = 64
2x - 14 = 64
2x = 64 + 14
2x = 78
x = 78/2
x = 39
Thus, The larger number is = 39
Then, the smaller number = 39 - 14
= 25
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Corinne has a job selling magazines. She earns $7.50 per hour plus 20% of the total amount of her sales. She also gets an allowance of $40 per week for gas. She knows her weekly earnings can be shown using the following expression: 7.50h + 0.20s + 40 Part A: Identify a coefficient, a variable, and a constant in this expression. (3 points) Part B: If Corinne works for 25 hours and sells $300 in magazines, how much does she earn for the week? Show your work to receive full credit. (4 points) Part C: If Corinne gets a raise and begins earning $9 per hour, would the coefficient, variable, or constant in the equation change? Why? (3 points) (10 points)
What is 65 percent converted into a fraction in simplest form\?
128 is the product of Julie's savings and 8
Use the variable j to represent Julie's savings.
128=8j; divide both sides by 8
j=16
Compare and contrast the perpendicular bisectors, medians, and altitudes of a triangle. How are they alike? How are they different?
The probability of winning on a split bet in a specific game of roulette is 1 19. Find the actual odds in favor of winning on the bet.
The answer is 1:18. I just took the statistics quiz and got it wrong due to the other person.
On a multiple choice test with 13 questions, each question has four possible answers, one of which is correct. for students who guess at all answers, find the standard deviation for the number of correct answers.
At 1:00 p.m. a car leaves st. louis for chicago, traveling at a constant speed of 65 miles per hour. at 2:00 p.m. a truck leaves chicago for st. louis, traveling at a constant speed of 55 miles per hour. if it is a 305-mile drive between st. louis and chicago, at what time will the car and truck pass each other?
To find out when the car and truck will pass each other, set up an equation where the sum of the distances covered by each at their respective speeds equals 305 miles. After solving, it's determined they will pass each other at 4:00 p.m.
To determine at what time the car and truck will pass each other, we need to calculate how far each vehicle will have traveled before they meet. The car leaves St. Louis at 1:00 p.m., while the truck leaves Chicago at 2:00 p.m., one hour later. We assume they meet after the car has been traveling for t hours and the truck for t - 1 hours.
The distance the car travels is the product of its speed and time, which can be calculated as 65 miles per hour times t hours. The truck's distance is 55 miles per hour times (t - 1) hours. Since the total distance between St. Louis and Chicago is 305 miles, we combine these distances to form the equation:
65t + 55(t - 1) = 305
Solving this equation:
65t + 55t - 55 = 305120t - 55 = 305120t = 305 + 55120t = 360t = 360 / 120t = 3 hoursSince the car has been traveling for 3 hours after 1:00 p.m., the two vehicles will pass each other at 4:00 p.m.
At the beginning of every year molly deposits 200 in a savings account thst offers 20% interest annually. The total amount molly woukd have in her account after 3 years is? I got 345.60 but wrong?
Sadie the dog is sitting on the roof of his doghouse, 4.5 ft off the ground. He is watching a cat that is 16 ft away from the base of the doghouse. What is the angle of depression from the roof of the doghouse to the cat? Round to the nearest hundredth. I watched the lesson but it all just went over my head, can someone simplify the explanation of how these problems work?
Circle A and circle B are congruent. CD is a chord of both circles. If AB = 8 ft and CD = 6 ft, how long is a radius?
Let us say that the intersection point of lines AB and CD is called point E. The lines AB and CD are perpendicular to each other which also means that the triangle CEB is a right triangle.
Where the line CB is the radius of the circle while the side lengths are half of the whole line segment:
EB = 0.5 AB = 0.5 (8 ft) = 4 ft
CE = 0.5 CD = 0.5 (6 ft) = 3 ft
Now using the hypotenuse formula since the triangle is right triangle, we can find for the radius or line CB:
CB^2 = EB^2 + CE^2
CB^2 = (4 ft)^2 + (3 ft)^2
CB^2 = 16 ft^2 + 9 ft^2
CB^2 = 25 ft^2
CB = 5 ft = radius
Answer:
5ft
Step-by-step explanation:
Let f(x)=√7x and g(x)=x+8, whats the smallest number that is the domain of f^o g?
Final answer:
The smallest number in the domain of the composite function f^o g, is -8.
Explanation:
To find the smallest number that is in the domain of the composite function fo g, we need to consider the domains of the individual functions f(x) and g(x). First, since f(x) = √7x, f is only defined for x ≥ 0, as the square root function requires non-negative input. Secondly, g(x) = x+8 is defined for all real numbers, as it's a linear function.
However, the composite function f(g(x)) will also require that the output of g(x) be non-negative, because this output becomes the input for f(x). Thus, we need to find the smallest x such that g(x) is non-negative, which occurs when x+8 ≥ 0. Solving for x gives us x ≥ -8.
Hence, the smallest x in the domain of fo g is -8.
A bridge is 28 meters long. Find the length of a scale model if the scale is 1 cm = 5.5 meters. Round to the nearest tenth.
a.
5.1 cm
c.
4.7 cm
b.
5.5 cm
d.
6.4 cm
Based on the length of the bridge and the scale used, the length of the scale model is a. 5.1 cm.
What is the length of the scale model?This can be found as:
= Length of Bridge / Number of meters per centimeters
Solving gives:
= 28 / 5.5
= 5.09
= 5.1 cm
In conclusion, option A is correct.
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Lisa and Kate are playing a card game, and a total of 900 points has been scored. Lisa scored 250 more points than Kate. If you let l=l=the number of points that Lisa scored, and k=k= the number of points that Kate scored, then the problem can be represented by the system:
l+k=900l+k=900 and l=k+250l=k+250
Graph the system. How many points did each of them score?
Select one:
a. Kate = 575 and Lisa = 325
b. Kate = 250 and Lisa = 650
c. Kate = 450 and Lisa = 450
d. Kate = 325 and Lisa = 575
Answer:
Lisa score 575 points and Kate scored 325 points.
Step-by-step explanation:
We are given the following information:
Total score for Lisa and Kate is 900 and Lisa scored 250 more points than Kate.
Scores for Lisa and Kate can be expressed with the help of two equations:
[tex]L + K = 900\\L = K + 250 \Rightarrow L-K = 250[/tex]
Solving these equations we have:
[tex]L + K + L - K = 900 + 250\\2L = 1150\\L = 575\\K = 575 - 250 = 325[/tex]
Hence, Lisa score 575 points and Kate scored 325 points.
The graph of the equations is attached.