Wednesday

September 2, 2015
**Calculus - HELP URGENT PLEASE**

The region R is bounded by the x-axis, x=2 and y=x^2. Which of these expressions represents the volume of the solid formed by revolving R about the line x=2?
*Sunday, August 9, 2015 by Ashley*

**Calculus 1**

Find the volume of the solid obtained by rotating the region under the graph of the function f(x)=2x+1 about the x-axis over the interval [0,1]. I have no clue how to start this..... :(
*Thursday, August 6, 2015 by Luke*

**calculus**

If the driver of a car wishes to increase his speed from 20 mph to 50 mph while traveling a distance of 528 ft., what constant acceleration should he maintain?
*Thursday, August 6, 2015 by jean*

**calculus**

a particle starts from rest and moves along a straight line with an acceleration equal to 24-15√t where distance and time are measured in terms of feet and seconds respectively. with what acceleration will the particle return to the starting point?
*Thursday, August 6, 2015 by jean*

**calculus**

A stone dropped from a ballon which was rising at the rate of 15 ft./sec. reached the ground in 8 seconds. how high was the ballon when the stone was dropped? please help :-) thank you
*Thursday, August 6, 2015 by jean*

**calculus**

Find the equation of the curve for which y''=6x-4 and which passes through (1,2) and (-2,5). thank you :-)
*Thursday, August 6, 2015 by justin*

**calculus**

Find the equation of the curve for which y'=3x² and which passes through (1,-1).
*Thursday, August 6, 2015 by justin*

**Calculus**

I have the question :A small blood vessel of radius 2mm branches off at an angle(theta) from a larger blood vessel of radius 4mm. According to Poiseuille's Law the total resistance to the blood flow is proportional to T=(a-bcot(theta)/4^4)+(bcsc(theta)/2^4) Show that the ...
*Thursday, August 6, 2015 by Jessica*

**calculus**

If dy=(2x+1)dx and y=7 when x=1, find the value of y when x=3.
*Thursday, August 6, 2015 by justin*

**Calculus**

My question is:Use L'Hospital's rule to find limit as x approaches 0 (e^x-e^-x-2x)/x-sinx. 1st I took the derivative to get (e^x-e^-x-2)/1+cosx. Substituting in 0, I got -1. The answer is supposed to be 2.I also tried (e^x-xe^-x-2)/1+cosx, and wound up with -(1/2). I ...
*Thursday, August 6, 2015 by Jessica*

**Calculus**

Can someone show how to solve this problem Find the equation of the tangent line to the curve given by, x=3e^t y=5e^-t at the point where t=0 Thanks!
*Wednesday, August 5, 2015 by Henry*

**Calculus**

Can someone show how to solve this problem Find the equation of the line normal to the graph of y = x^2 + 1 that passes through the point (1, 2). Thanks!
*Wednesday, August 5, 2015 by Henry*

**Calculus**

Find the area bounded by the y-axis and x = 4-y^2/3 Thanks!
*Tuesday, August 4, 2015 by Gela*

**Calculus**

The area bounded by the curve y^2 = 12x and the line x=3 is revolved about the line x=3. What is the volume generated?
*Tuesday, August 4, 2015 by Gela*

**calculus**

a parachutist falling at the rate of 15 ft./sec. drops a stone. if he was 904 ft. above the ground when the stone was dropped, how long would it take the stone to reach the ground?
*Tuesday, August 4, 2015 by jean*

**calculus**

a particle moves according to the law a=1/t √t. if s=8 when t=1. and s=16 when t=4. find v when t=9.
*Tuesday, August 4, 2015 by jean*

**Calculus**

The region in the first quadrant bounded by the x-axis, the line x = ln(π), and the curve y = sin(ex) is rotated about the x-axis. What is the volume of the generated solid? Got 2.8 and .79 very confused
*Tuesday, August 4, 2015 by Ali*

**Calculus**

Please help simplify this expression: 2 log (base 4) ^9 - log (base 2) ^3 The answer should be log(base 2) ^3
*Tuesday, August 4, 2015 by Alisha*

**Calculus**

Find the area bounded by the y-axis and x = 4-y^2/3
*Tuesday, August 4, 2015 by Rose*

**Calculus **

(1-sin^2 theta) - (sin^2 theta) (1-sin^2 theta) * (sin^2 theta)
*Thursday, July 30, 2015 by Seany*

**Calculus - Rate of Change**

Can someone explain how to solve this problem? Sand is being dumped on a conveyor belt onto a pile in such a way that the pile forms in the shape of a cone whose radius is always equal to its height. Assuming that the sand is being dumped at a rate of 10 cubic feet per minute...
*Wednesday, July 29, 2015 by Fred*

**Calculus**

An airplane is heading at a bearing of N23°E at a speed of 700 km/hr, but there is a wind blowing from the west at 60 km/hr. If the plane does not make any correction, what will be the bearing of the plane? What is its speed relative to the ground (ground speed = airspeed...
*Wednesday, July 29, 2015 by Alexa*

**calculus**

what is the interval notation for solution set of the inequality x^2+16x is less than or equal to 0
*Wednesday, July 29, 2015 by Hazel*

**Calculus**

The base of a solid in the first quadrant of the xy plane is a right triangle bounded by the coordinate axes and the line x + y = 2. Cross sections of the solid perpendicular to the base are squares. What is the volume, in cubic units, of the solid?
*Tuesday, July 28, 2015 by Ali*

**Calculus**

Can someone show how to solve this problem Two vertical towers of heights 60 ft and 80 ft stand on level ground, with their bases 100 ft apart. A cable that is stretched from the top of one pole to some point on the ground between the poles, and then to the top of the other ...
*Monday, July 27, 2015 by Hank*

**pre-calculus **

which expression is equivalent to (sinx+1)(sinx-1)? A.) COS^2X B.) -COS^2X C.) COS^2X+1 D.) COS^2X-1 E.) -COS^2X+1
*Monday, July 27, 2015 by Daisy*

**pre-calculus **

find the exact value of sin 112.5 in fraction form
*Monday, July 27, 2015 by Daisy*

**pre-calculus **

which of the following is a solution to 3tan^3x=tanx? A.) 60 degrees B.) 120 degrees c.)150 degrees D.)240 degrees E.)300 degrees
*Monday, July 27, 2015 by Daisy*

**pre-calculus **

Which of the following is NOT a solution to cos^2x=3sin^2x? A.) 30 degrees B.) 60 degrees C.) 150 degrees D.)210 degrees E.)330 degrees
*Monday, July 27, 2015 by Daisy*

**pre-calculus **

What is the exact value of sin 225
*Monday, July 27, 2015 by Daisy*

**calculus problem I have tried 100 times**

A tank in the shape of an inverted right circular cone has height 5 meters and radius 4 meters. It is filled with 2 meters of hot chocolate. Find the work required to empty the tank by pumping the hot chocolate over the top of the tank. The density of hot chocolate is δ=...
*Sunday, July 26, 2015 by Anonymous*

**Calculus**

My teacher wants me to use this formula for half life question C(t) = Ce^-kt but i used a different formula plz help. the question is: A radioactive isotope has a half life of 30 years. If we started off with 10 mg of this isotope 12 years ago: a) Find and expression for the ...
*Sunday, July 26, 2015 by max*

**Calculus**

Show that the limit as h approaches 0 of (e^h-1 ) all over h = ln e = 1 using at least two numerical examples.
*Sunday, July 26, 2015 by Jonathan*

**Calculus**

Find the derivative of the following functions using the f prime of x = the limit as h approaches 0 of f(x+h) – f(x) all over h a)ƒ(x) = x2 + 5^x b)ƒ(x)= 1/2^x
*Sunday, July 26, 2015 by Jonathan*

**Integral calculus**

The length of each leg of an isosceles right triangle is increase at the rate of 2 mm/s. How fast is the hypotenuse increasing at the moment when each leg is 10 mm?
*Saturday, July 25, 2015 by paula*

**Calculus**

Can someone explain how cos(X)/ square root (sin (X)) is 2 square root sin(x) +c Thanks!
*Thursday, July 23, 2015 by John*

**Calculus**

Givenƒ(x) = ex, verify that lim h->0 (e^x+h - e^h)/h + e^x and explain how this illustrates that ƒ′(x) = ln e • ƒ(x) = ƒ(x)
*Wednesday, July 22, 2015 by Jonathan*

**calculus**

find volumes of solids generated by revolving the regions bounded by the graphs of the equations about the given lines. y=square root of x y=0 x=3
*Wednesday, July 22, 2015 by Pam*

**calculus**

A cylindrical tank is to have a capacity of 1000 m³. It is to fit into a foundry that is 12 m wide with a height of 11 m. The base of the tank will cost half as much as the top. The metal for the side of the tank will cost four fifths as much as the top. An equation that ...
*Wednesday, July 22, 2015 by nal*

**Calculus**

(0.064)(2*pi*h)+(0.064)*4*pi*r=z*2*pi*r*h (0.064)2*pi*r=z*pi*r^2 pi*r^2*h=1567.8 Find r,h,z
*Wednesday, July 22, 2015 by Mars*

**calculus**

how to find surface area of a cylinder with respect to r(radius) and h(height)?
*Tuesday, July 21, 2015 by RR*

**calculus**

Sketch the region in the first quadrant enclosed by y=6/x, y=2x, and y=.5x. Decide whether to integrate with respect to x or y. Then find the area of the region. need final area as answer please, and step would be helpful also if you can post.
*Sunday, July 19, 2015 by Nick*

**Calculus**

Can someone show how this question is solved. Consider the curve given by the equation 2y^3 + y^2 - y^5 = x^4 -2x^3 +x^2 Find all points at which the tangent line to the curve is horizontal or vertical. Thanks!
*Saturday, July 18, 2015 by Henry*

**calculus**

Sketch the region in the first quadrant enclosed by y=6/x, y=2x, and y=12x. Decide whether to integrate with respect to x or y. Then find the area of the region.
*Saturday, July 18, 2015 by Nick*

**calculus**

The temperature of a hard boiled egg varies according to Newton's Law of Cooling: dT dt equals negative k times the quantity T minus A, where T is the temperature of the egg, A is the room temperature, and k is a positive constant. If the egg cools from 100°C to 90°...
*Friday, July 17, 2015 by Anonymous*

**calculus**

Find the particular solution to y ′ = sin(x) given the general solution is y = C − cos(x) and the initial condition y(pi/2)=1
*Friday, July 17, 2015 by Anonymous*

**calculus**

The rate of decay in the mass, M, of a radioactive substance is given by the differential equation dM dt equals negative 1 times k times M, where k is a positive constant. If the initial mass was 100g, then find the expression for the mass, M, at any time t.
*Friday, July 17, 2015 by Anonymous*

**calculus**

Newton’s law of cooling states that the rate of cooling of an object is proportional to the temperature difference between the object and its surroundings. So the rate of cooling for a bottle of lemonade at a room temperature of 75°F which is placed into a ...
*Thursday, July 16, 2015 by Anonymous*

**Calculus**

My question is finding the derivitive of y=((x+λ)^4)/(x^4+λ^4). I distributed the exponent in the numerator, but I don't know if that's right. Rewritten as y=(x^4+λ^4)/(x^4+λ^4). I found the derivitive and multiplied accordingly, as ((4x^3+4λ^3...
*Wednesday, July 15, 2015 by Jessica*

**Calculus**

So, I have a homework question on The Quotient Rule (taking derivitives) and I would like to know if I did it right. Calculate: y=(1/sqrt(x))-(1/(5th root of x^3). My 1st step was to change the sqrt to x^1/2, and the 5th root to x^1/5+^3. So then I got y=(1/x^1/2)-(1/x^16/5). ...
*Wednesday, July 15, 2015 by Jessica*

**Calculus Partial Derivatives**

Verify that the sum of three quantities x, y, and z, whose product is a constant k, is maximum when these three quantities are equal.
*Wednesday, July 15, 2015 by Anonymous*

**calculus**

Sketch the region enclosed by the given curves. Decide whether to integrate with respect to x or y. Then find the area of the region. y=3+√X, y=3+1/5x What is the area?
*Tuesday, July 14, 2015 by Nick*

**Calculus**

y = g(x) = cos(x) Can someone show how to estimate g'(pi/2) using the limit definition of the derivative and different values of h. Thanks!
*Sunday, July 12, 2015 by Henry*

**Calculus Partial Derivatives**

Problem: Find dimensions of a box that provide the greatest volume when the length plus the girth cannot exceed six feet. I tried 2w+2h+l=6, l=6-2w-2h, but couldn't get to w=1, h=1, l=2, which is the correct answer.
*Friday, July 10, 2015 by Anonymous*

**Calculus Partial Derivatives**

y=F(x+at) + f(x-at) y=F(w) + f(v) (w=x+at, v=x-at) don't see how to get from here to partial derivative y with respect to t = F"(w)a^2 + f"(v)a^2
*Thursday, July 9, 2015 by Anonymous*

**Calculus**

Can someone provide a function that satisfies all of the following: • p(−1) = 3 and lim x→−1 p(x) = 2 • p(0) = 1 and p'(0) = 0 • lim x→1 p(x) = p(1) and p'(1) does not exist Thanks!
*Wednesday, July 8, 2015 by Henry*

**Calculus**

1. Provide an example of a function f that is continuous at a = 2 but not differentiable at a = 2. 2. Provide an example of a function g that is differentiable at a = 3 but does not have a limit at a = 3. Thanks!
*Wednesday, July 8, 2015 by Andy*

**Calculus**

Please simplify the expression: 2log(base 4)9 - log(base 2)3
*Wednesday, July 8, 2015 by Alisha*

**Calculus**

Simplify: (5x^3 + x^2 - x)/ (3x)
*Wednesday, July 8, 2015 by Mona*

**Calculus**

I have a graph of f(x) which I cant post here, but would like some help with concepts. lim f(x) = L x->a I already found the limit for different values of a. Now I need to find the value of f(a) at each point. So is f(a) = lim f(x) x->a So f(a) is just the same value of ...
*Tuesday, July 7, 2015 by George*

**Calculus**

Determine over what interval(s) is the function y=4x-6arctan(x) is concave up/concave down I took the second derivative and ended up with x=0. I do not believe I did this right. IF I happen to be right, wouldn't our answer just be undefined, rather than having intervals ...
*Tuesday, July 7, 2015 by John*

**Calculus AB**

Find the limit as x->infinity of ((3x+2)/(3x+4))^(3x+1)
*Tuesday, July 7, 2015 by Patricia*

**Calculus**

Find max or min: y = x * cosx
*Tuesday, July 7, 2015 by Anonymous*

**Calculus**

log (base 3) x^2 = 2log(base 3)4-4log(base 3)5 And I need to solve for x.
*Monday, July 6, 2015 by Mona*

**Calculus**

The velocity of a ball that has been tossed vertically in the air is given by v(t) = 16 − 32t, where v is measured in feet per second, and t is measured in seconds. The ball is in the air from t = 0 until t = 2. Determine the value of v'(1). What are the units on the...
*Monday, July 6, 2015 by George*

**pre calculus **

32% of a particular radioactive substance disappears in 227 years. Part 1: Find the decay constant. Your answer must be correct to five decimal places. Part 2: Determine the time T in years required for 93% of the substance to disapper. Your answer must be correct to two ...
*Monday, July 6, 2015 by Morgan*

**Calculus **

A particle moves on a vertical line so that its coordinate at time t is 3 y = t − 12t+ 3, t≥ 0 . When is the particle moving upward and when is it moving downward? Find the distance that the particle travels in the first 3 seconds. I got that t=2 and t=-2 and its ...
*Sunday, July 5, 2015 by John*

**Calculus**

How do the constants 5, 4, and 12 in f(x) = 5x^2 - 4x + 12, affect the derivative? Thanks!
*Sunday, July 5, 2015 by Fred*

**calculus**

radioactive Carbon 14 in a dead organism decays according to the equation A=A e^.000124t where t is in years and A0 is the amount at t=0. Estimate the age of a skull uncovered in an archeological site if 10% of the original Carbon 14 is still present.
*Friday, July 3, 2015 by veronica*

**Calculus Minimum**

Problem: Find minimum?maximum for: y=xa^(1/x) Ans given: X=ln(a) (min) Can't get to it.
*Thursday, July 2, 2015 by Anonymous*

**Calculus**

Find the limit of cosx/(1-sinx) as x->(pi/2) from + side
*Thursday, July 2, 2015 by Patricia*

**calculus**

calculate the largest area possible that can be made by a 15 meter long wire that will be bent to form a closed plane area. No figure given
*Thursday, July 2, 2015 by Jhun*

**calculus**

Car A is 30 mi apart from car b. Car A moves 30 mph due east at the same time car b moves 30 degrees south of east. how fast is the distance between them changing after an hour.
*Thursday, July 2, 2015 by Jhun*

**calculus**

p=-1/5x+200 Cost of a Commodity. The price p, in dollars, of a certain commodity and the quantity x sold. Obey the demand equation. p= -1/5x+200
*Wednesday, July 1, 2015 by Anonymous-2*

**Calculus Derivative**

Find derivative: y= e^(x^x)
*Wednesday, July 1, 2015 by Anonymous*

**Differential calculus**

The voltage across the plates of a capacitor at any time t seconds is given by V=Ve -t/CR, where V,C and r are constants. Given V = 300 Volts, C =0.12*10-6 F and R = 4*10 6 ohms Find the initial rate of change of voltage and the rate of change of voltage after 0.5 seconds
*Tuesday, June 30, 2015 by lee*

**calculus**

Find the complex zeros of the polynomial function. F(x)=5x^4-16x^3-22x^2+200x-39
*Tuesday, June 30, 2015 by Anonymous-2*

**Calculus**

A rectangular page is to contain 72 square inches of print. The page has to have a 4 inch margin on top and at the bottom and a 2 inch margin on each side. Find the dimensions of the page that minimize the amount of paper used.
*Monday, June 29, 2015 by Uri*

**calculus**

Cost of a Commodity. The price p, in dollars, of a certain commodity and the quantity x sold. Obey the demand equation. p= -1/5x+200
*Sunday, June 28, 2015 by Anonymous-2*

**Calculus Partial Fraction**

Sorry. The problem should have been: (x^2)/(x^3-8)(x-2)
*Sunday, June 28, 2015 by Anonymous*

**Calculus Partial Fraction**

(x^2)/(x^3)(x-2)
*Sunday, June 28, 2015 by Anonymous*

**Calculus, derivatives**

Derivative of y=(a^x)+(x^a). Show steps, please.
*Saturday, June 27, 2015 by Walt*

**Pre Calculus**

Let θ be an angle in quadrant IV such that cosθ = 4/9. Find the exact values of csc θ and cot θ. I am just completely lost! Thanks!
*Friday, June 26, 2015 by Anonymous*

**Calculus**

Demand Equation. The price(in dollars),and the quantity x sold of a certain product, obey the demand equation. I can't figure out what price the company should charge to maximize revenue p=-1/10x+150 R=p*x R=((-1/10)*x+150)*x R=(-1/10)*x^2+150x y=ax^2+b*x+c a=-1/10 b=150 c...
*Monday, June 22, 2015 by Anonymous-1*

**Calculus(math)**

A particle is moving on a straight line in such a way that its velocity v is given by v(t)=2t+1 for 0≤t≤5 where t is measured in seconds and v in meters per second. What is the total distance traveled (in meters) by the particle between times t=0 seconds and t=5 ...
*Sunday, June 21, 2015 by Alice*

**calculus**

The base of a solid is the circle x2 + y2 = 9. Cross sections of the solid perpendicular to the x-axis are equilateral triangles. What is the volume, in cubic units, of the solid?
*Sunday, June 21, 2015 by Anonymous*

**Calculus AB**

Gateway Arch in St. Louis was constructed using the equation y=211.49-20.96cosh(0.03291765x) where |x|<=91.20 a) what is the height at its center in meters b) At what points is height 70m (2 values of x) c) what is the slope of arch at points in part b
*Sunday, June 21, 2015 by Patricia*

**Calculus**

Using a graphing calculator and the concept of differentials determine the values for x when 1/(1+3x)^5 is approx = to (1-15x) within .01
*Sunday, June 21, 2015 by Greg*

**Calculus**

Ferris wheel has radius of 26m. At what rate is the rider's height increasing, when rider is 25 m from ground.
*Sunday, June 21, 2015 by Mike*

**pre-calculus**

Steve, The following rational function describes concentration in blood of a certain medicine taken once depending on time, find: A. the horizontal asymptote B. the vertical asymptote C. describe their possible meaning ( I only need help with C). f(x)=x/x^2-100 Sharon
*Saturday, June 20, 2015 by Sharon*

**pre-calculus**

The following rational function describes concentration in blood of a certain medicine taken once depending on time, find: A. the horizontal asymptote B. the vertical asymptote C. describe their possible meaning ( I only need help with C
*Saturday, June 20, 2015 by Sharon*

**Calculus**

Using differentials find dy and delta y when y=7/x and dx=delta x =1
*Saturday, June 20, 2015 by Pat*

**Calculus**

two sides of triangle are 10m and 19m and the angle between them is increasing at a rate of 2 degrees per minute. How fast is the third side changing when the angle between them is 60 degrees
*Saturday, June 20, 2015 by Pat*

**Calculus**

A 0.9 ml dose of a drug is injected into a patient steadily for half a second. At the end of this time, the quantity, Q, of the drug in the body starts to decay exponentially at a continuous rate of 0.4% per second. Using formulas, express Q as a continuous function of time, t...
*Thursday, June 18, 2015 by Devon*

**calculus**

The following rational function describes concentration in blood of a certain medicine taken once depending on time, find: A.the horizontal asymptote(s) B.the vertical asymptote(s) C. describe their possible meanings Horizontal asymptote is y=-100 vertical asymptotes are x=-10...
*Wednesday, June 17, 2015 by Sharon*

**Calculus**

One side of a rectangular animal pen is to be formed by the side of a barn. If you have enough material to build a total of 34 feet of fence, find the maximum area than can be enclosed
*Wednesday, June 17, 2015 by Bella*

**Calculus**

Okay, so I worked out 17 = T(10) = 2 + 23e ^10k 15/23 = e^10k k= 1/10ln(15/23) k = - 0.043 But when I do this equation 17 = T(30) = 2 + 23e^30k 15/23 = e^30k k = 1/30ln(15/23) k = -0.142 But the answer is apparently 8.38? Can someone please help. I think I'm getting too ...
*Wednesday, June 17, 2015 by Anonymous*

**pre-calculus 11 **

I have a question that two ski decide to have a race. I need show a graph of height versus time of the two skiers going over a jump. I am assuming that both skiers graphs would be parabola's and have a maximum height with both graphs opening downward.
*Tuesday, June 16, 2015 by george *

**pre-calculus 11**

The infinite series 1+3x +9x^2 +27x^3+.. has a sum of 4.The value of x is? so if 1/1-r I substitute 1/1-3x =4 so x=1/4 if someone could confirm that my answer is correct? thanks so much
*Tuesday, June 16, 2015 by george *

**pre-calculus 11 **

The question is the roundtrip flight from Edmonton to Toronto covers a distance of 5400km in 7.6 hours. The speed from Edmonton to Toronto was 95 km/h faster than the speed from Toronto to Edmonton. What was the speed of the plane from Toronto to Edmonton? If i set up my ...
*Tuesday, June 16, 2015 by george *