Wednesday

November 25, 2015
**Math (calculus)**

If y = 2x^3 - 4x and dx/dt = 4, find dy/dt when x = 1. Please show me how to solve this problem with steps.
*Saturday, January 10, 2015 by Dan*

**Calculus**

Evaluate each telescoping sum: 1) Sum from i = 1 to 100 of (5^i - 5^(i-1)). I know that I could apply the (n(n+1))/2 summation rule to the 5^i part of the question and then plug in 100, but I am unsure what to do for the second half --> -5^(i-1)! Thank you for any help!
*Friday, January 9, 2015 by Lucy*

**college pre-calculus**

what is the equation of lowest degree with real coefficients if two of its roots are -1 and 1+i? A. x^3+x^2+2=0 B. x^-x^2-2=0 C. x^3-x+2=0 D. x^3-x^2+2=0 e. none of the above i dont get it is it (x+1) (1+i)
*Tuesday, January 6, 2015 by kyle*

**Calculus**

a balloon rises straight up to 5 ft/sec. and a crying child who lost the balloon is standing 40 ft away. how fast does the balloon move away from the child when it is 30 ft above the ground?
*Sunday, January 4, 2015 by Anon*

**calculus**

finding first derivative for functions y=x³In(5x)
*Saturday, January 3, 2015 by sharon*

**Calculus**

∫csc x cot^2 xdx
*Saturday, January 3, 2015 by Anonymous*

**calculus**

Y =-( x+2)² - 4 state clearly intercept x and intercept Y
*Saturday, January 3, 2015 by arul*

**Calculus**

The function h(x) = x^3+bx+d has a critical point at (2,-4). Determine the constants b and d and find the equation of h(x). I'm very confused and I do not have any idea on what the first step is.
*Friday, January 2, 2015 by Daniel*

**Calculus**

The function h(x) = x^3+bx+d has a critical point at (2,-4). Determine the constants b and d and find the equation of h(x). Show your work.
*Friday, January 2, 2015 by Daniel*

**calculus**

this is an exploration in my textbook that we are assigned to do. it basically means we are supposed to use our graphing calculator to help. my calculator won't work for some reason so I'm trying to do it without and cannot figure it out. the question is really ...
*Thursday, January 1, 2015 by emilia``*

**Calculus**

f(x)= x/(1+x)^2 c) find the intervals of concavity and the inflection points. My answers: f is concave downward on (- infinity, 2) and concave upward on (2, infinity). Inflection point: ( 2, 2/9)
*Wednesday, December 31, 2014 by Anonymous*

**Calculus**

I don't get how you get this part: f' = (1-x)/(1+x)^3 f" = [(-1)(x+1)^3 - 3(1-x)(x+1)^2]/(x+1)^6 = [-(x+1)+3(x-1)]/(x+1)^4 ( I don't understand how you got this!!) = (-x-1+3x-3)/(x+1)^4 = (2x-4)/(x+1)^4
*Wednesday, December 31, 2014 by Anonymous*

**Calculus**

What is the derivative of f(x)=(10-3x)/2• sqrt of (5-x)?
*Wednesday, December 31, 2014 by Anonymous*

**calculus**

I really don't know where to start or go with this question...There aren't any similar examples in my book so if you could walk me through it so I can be prepared for my test - that would be great! Thanks. (a) Approximate √26 by using the linearization of y=&#...
*Wednesday, December 31, 2014 by Tenley*

**Calculus**

How would I find out what the height of the pile would be after 5 minutes? A machine starts dumping sand at the rate of 20 m3/min, forming a pile in the shape of a cone. The height of the pile is always twice the length of the base diameter. The volume formula for a right ...
*Wednesday, December 31, 2014 by Peter*

**Calculus **

f(x)= x/(1+x)^2 a) find the intervals on which f is increasing or decreasing. Is it ....f is decreasing on the intervals (- infinity, -1) and (1, infinity)...f is increasing on the interval (-1, 1)....... b)find the local min and max values of f.. For f(-1) I got undefined... ...
*Wednesday, December 31, 2014 by Anonymous*

**Calculus**

a) find the intervals on which f is increasing or decreasing. Is it ....f is decreasing on the intervals (- infinity, -1) and (1, infinity)...f is increasing on the interval (-1, 1)....... b)find the local min and max values of f.. For f(-1) I got undefined... f(1)=1/4....... ...
*Wednesday, December 31, 2014 by Anonymous*

**Pre-Calculus**

How do you solve the equation(800+x)tan33=xtan35?
*Monday, December 29, 2014 by Angie*

**Calculus- Can you help me solve for dr/dt**

How fast does the radius of a spherical soap bubble change when you blow air into it at the rate of 15 cubic centimeters per second? Our known rate is dv/dt , the change in volume with respect to time, which is 15 cubic centimeters per second. The rate we want to find is dr/dt...
*Monday, December 29, 2014 by Rachel*

**calculus**

A rectangular box has a square base with an edge length of x cm and a height of h cm. The volume of the box is given by V = x^2h cm^3. Find the rate at which the volume of the box is changing when the edge length of the base is 12 cm, the edge length of the base is decreasing ...
*Monday, December 29, 2014 by Anonymous*

**calculus**

A rectangular box has a square base with an edge length of x cm and a height of h cm. The volume of the box is given by V = x^2h cm^3. Find the rate at which the volume of the box is changing when the edge length of the base is 4 cm, the edge length of the base is increasing ...
*Monday, December 29, 2014 by Anonymous*

**Calculus**

evaluate each of the following integral:- I= ∫((x^2+ 1)/(x^4+ 1))dx Y=∫(sinhxcoshx)dx/√(sinhx^4+coshx^4)
*Sunday, December 21, 2014 by NA*

**Calculus**

If 3x^2+y^2=7 evaluate ((d^2)y)/(dx^2) when x=1 and y=2
*Sunday, December 21, 2014 by John*

**calculus**

use implicit differentiation to find y=(x+8)^(3x)
*Sunday, December 21, 2014 by John*

**Calculus **

Determine the equation of the normal line y=x^2+5 at the point (2, 9) I got y= 4x+1
*Sunday, December 21, 2014 by Olivia*

**Calculus**

Determine the intersection, if any, of the planes with equations x + y - z + 12 = 0 and 2x + 4y - 3z + 8 = 0. I have no clue where to even begin. If someone could help and give me the steps to complete it, that would be greatly appreciated. Do I have to first simplify the ...
*Thursday, December 18, 2014 by Ad*

**Calculus**

Determine the intersection, if any, of the planes with equations x + y - z + 12 = 0 and 2x + 4y - 3z + 8 = 0. I have no clue where to even begin. If someone could help and give me the steps to complete it, that would be greatly appreciated. Do I have to first simplify the ...
*Thursday, December 18, 2014 by Ad*

**Pre-Calculus**

Can you create another pair of six-sided dice (different from the standard dice) that produces the exact same probabilities of the sums two through twelve appearing? The only rule is that the numbers on each face must be positive integers. I've been attempting this problem...
*Wednesday, December 17, 2014 by Evelyn*

**Calculus **

find the absolute extrema for f(x)= (5-x) with a closed interval of -1,2
*Wednesday, December 17, 2014 by AC*

**AP AB Calculus**

Linear approximation: Consider the curve defined by -8x^2 + 5xy + y^3 = -149 a. find dy/dx b. write an equation for the tangent line to the curve at the point (4,-1) c. There is a number k so that the point (4.2,k) is on the curve. Using the tangent line found in part (b), ...
*Wednesday, December 17, 2014 by Katie G*

**calculus honor**

If y = 2x3 – 4x and , find when x = 1. Give only the numerical answer. For example, if = 3, type only 3.
*Wednesday, December 17, 2014 by Anonymous*

**calculus honor**

A rectangular box has a square base with an edge length of x cm and a height of h cm. The volume of the box is given by V = x2h cm3. Find the rate at which the volume of the box is changing when the edge length of the base is 4 cm, the edge length of the base is increasing at ...
*Wednesday, December 17, 2014 by Anonymous*

**calculus**

The height of a cylinder with a fixed radius of 6 cm is increasing at the rate of 3 cm/min. Find the rate of change of the volume of the cylinder (with respect to time) when the height is 20cm.
*Wednesday, December 17, 2014 by Anonymous*

**calculus**

The area A = πr2 of a circular puddle changes with the radius. At what rate does the area change with respect to the radius when r = 5ft?
*Wednesday, December 17, 2014 by Anonymous*

**Calculus **

Average value of f(x) = e ^ 4xsquared on the interval [-1/4,1/4]
*Tuesday, December 16, 2014 by Star*

**calculus**

No idea where to start The cost in dollars of producing x units of a particular camera is C(x) = x2 - 10000. (10 points) Find the average rate of change of C with respect to x when the production level is changed from x = 100 to x = 101. Include units in your answer. Find the ...
*Tuesday, December 16, 2014 by John*

**calculus**

Do I just put in 3 for t? A ball is dropped from a tower 550 meters above the ground with position function s(t) = 4.9t2 + 550. What is the velocity of the ball after 3 seconds?
*Tuesday, December 16, 2014 by John*

**Calculus**

Given the function f(x)= x√(x+3), Indicate the domain of f(x): ………………
3;……… What are the x – intercepts of the graph of f(x)? POINTS! ………………
3;…………. ...
*Tuesday, December 16, 2014 by Anonymous*

**calculus**

A 25-ft ladder rests against a vertical wall. If the bottom of the ladder slides away from the wall at a rate of 0.18 ft/sec, how fast, in ft/sec, is the top of the ladder sliding down the wall, at the instant when the bottom of the ladder is 20 ft from the wall?
*Tuesday, December 16, 2014 by Anonymous*

**Calculus**

Find the derivative of 1/(1+(x-3)^2) Steps would be appreciated.
*Monday, December 15, 2014 by Dan*

**calculus**

there are no examples of this type of problem in my book so if you could help walk me through it - that would be extremely helpful. thanks ahead of time. Find the extreme values of the function on the interval and where they occur. 4) F(x)=³√(x); -3</=x</=64 A...
*Monday, December 15, 2014 by K.T.*

**Calculus **

Use linear approximation to approximate f(0.8) given f(x)=2x^3-3x+1 I'm not sure how to do it without a point given.
*Monday, December 15, 2014 by Anonymous *

**Calculus (math)**

The volume of the solid obtained by rotating the region enclosed by y=1/x4,y=0,x=1,x=6 about the line x=−2 can be computed using the method of cylindrical shells via an integral. it would be great if you can just even give me the function inside that I need to take the ...
*Monday, December 15, 2014 by Thank you in advance :)*

**Calculus (math)**

The velocity function (in meters per second) for a particle moving along a line is given by v(t)=t3−5t2. Find the displacement and the distance traveled by the particle during the time interval [-1,6]. Distance traveled = ?? I got 2089/12m as answer but it was incorrect ...
*Sunday, December 14, 2014 by Help me plz!*

**Calculus (math)**

A bacteria culture grows with constant relative growth rate. The bacteria count was 784 after 2 hours and 117649 after 6 hours. What is the relative growth rate? What was the initial size of the culture? Find an expression for the number of bacteria after t hours. Find the ...
*Sunday, December 14, 2014 by Help me plz!*

**Calculus (math)**

Warfarin is a drug used as an anticoagulant. After administration of the drug is stopped, the quantity remaining in a patient's body decreases at a rate proportional to the quantity remaining. Suppose that the half-life of warfarin in the body is 35 hours. Write a ...
*Sunday, December 14, 2014 by luna*

**Calculus (math)**

A tank in the shape of an inverted right circular cone has height 7 meters and radius 4 meters. It is filled with 5 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, December 14, 2014 by Help!!*

**Calculus (math)**

A group of engineers is building a parabolic satellite dish whose shape will be formed by rotating the curve y=ax2 about the y-axis. If the dish is to have a 8-foot diameter and a maximum depth of 2 feet, find the value of a and the surface area (in square feet) of the dish.
*Sunday, December 14, 2014 by mariel*

**Calculus (math)**

Consider the area between the graphs x+3y=35 and x+5=y2. This area can be computed in two different ways using integrals
*Sunday, December 14, 2014 by mia*

**Calculus**

Show that Rolle's Theorem applies to the given function for the given values of x: x=-1 and x=4 for f(x)=3x-x^2+2.
*Sunday, December 14, 2014 by Anonymous*

**Calculus **

Consider the function y = 3x5 – 25x3 + 60x + 1. Use the first derivative test to decide whether this function has a maximum at x = 1
*Sunday, December 14, 2014 by Carey*

**calculus**

Given f(x,y,z)=<y,z^2-x,x> use stokes theorem to determine the flux integral curlF dot ds, where S is the graph of z=9 - x^2 - y^2 for z>=0 , oriented by the upward normal. please help!
*Sunday, December 14, 2014 by sam*

**Calculus**

Let f(x) be a polynomial function such that f(-2)=5, f'(-2)=0, and f"(-2)=3. The point (-2,5) is a(n)____of the graph f. A. Relative maximum B. Relative minimum C. Intercept D. Point of Inflection E. None of these
*Sunday, December 14, 2014 by Anonymous*

**Calculus**

Use linear approximation to approximate f(0.8) given f(x)=2x^3-3x+1
*Sunday, December 14, 2014 by Anonymous*

**AP Calculus**

The management of a large store has 1600 feet of fencing to fence in a rectangular storage yard using the building as one side of the yard. If the fencing is used for the remaining 3 sides, find the area of the largest yard possible.
*Sunday, December 14, 2014 by Sarah*

**Calculus**

Find the x-values where f(x)=x^4-8x^3 attains a relative minimum, relative maximum, and inflection points, if any. Justify your answers. My derivative test didn't seem right.
*Sunday, December 14, 2014 by Anonymous*

**Calculus**

Show that Rolle's Theorem applies to the given function for ht eg oven values of x: x=-1 and x=4 for f(x)=3x-x^2+2
*Sunday, December 14, 2014 by Anonymous*

**Calculus**

A baseball diamond is a square with side 90 ft. a batter hits the ball and runs toward first base with a speed of 24 ft/s. (a) At what rate is his distance from second base decreasing when he is halfway to first base? Is the answer 0.0932ft/s? I don't see that it is ...
*Sunday, December 14, 2014 by Anonymous*

**Calculus**

A boat is pulled into a dock by a rope attached to the bow of the boat and passing through a pulley on the dock that is 1 m higher than the bow of the boat. If the rope is pulled in at a rate of 1m/s,how fast is the boat approaching the dock when it is 8 m from the dock?
*Sunday, December 14, 2014 by Anonymous*

**Calculus**

A baseball diamond is a square with side 90 ft. a batter hits the ball and runs toward first base with a speed of 24 ft/s. (a) At what rate is his distance from second base decreasing when he is halfway to first base? (b) At what rate is his distance from third base increasing...
*Sunday, December 14, 2014 by Anonymous*

**Calculus**

A baseball diamond is a square with side 90 ft. a batter hits the ball and runs toward first base with a speed of 24 ft/s. (a) At what rate is his distance from second base decreasing when he is halfway to first base? (b) At what rate is his distance from third base increasing...
*Sunday, December 14, 2014 by Anonymous*

**calculus**

The graph of a function f is shown. Use the differential equation and the given point to find an equation of the function. dy/dx=4x+(9x^2/(3x^3+1)^(3/2)) and the point (0,2) using the substitution method of integration.
*Sunday, December 14, 2014 by JT*

**Calculus 1**

A woman at a point A on the shore of a circular lake with radius r=4 wants to arrive at the point C diametrically opposite A on the other side of the lake in the shortest possible time. She can walk at the rate of 10mph and row a boat at 5mph. What is the shortest amount of ...
*Saturday, December 13, 2014 by Rainbows*

**Calculus**

Find the length of the entire perimeter of the region inside r=15sin(theta) but outside r=1. I am not sure how to start the problem
*Friday, December 12, 2014 by Susan*

**Calculus **

My question: An equation of the line tangent to the graph of f(x) = x(1 - 2x)3 at the point (1, –1) is?? My answer: y = –2x + 1
*Thursday, December 11, 2014 by Jenny*

**Math-Calculus**

Find the point on the line -2x + 4y + 3 =0 which is closest to the point (-2,1). Note: I have been struggling on this for hours!
*Thursday, December 11, 2014 by Jacob*

**calculus**

after t seconds the position of a particle which is moving along a straight line is x=2t^3-9t^2+12t+6, when is the acceleration zero? determine the velocity at that time.
*Thursday, December 11, 2014 by khai*

**Calculus**

Hi! I need help with this problem: For 0(smaller or equal to) t (smaller or equal to) 9, a particle moves along the x-axis. The velocity of the particle is given by v(t)= (sin pi/4 t). The particle is at position x= -4 when t=0. a) For 0 (smaller or equal to) t (smaller or ...
*Thursday, December 11, 2014 by Dana*

**calculus **

lim(x tends to 3) (square root(x^2+7) -4) divided by (square root(x^2-8) -1) Pls help and list the steps. Thx
*Wednesday, December 10, 2014 by ivan*

**Calculus**

If the y-coordinate at each point of inflection on the curve y=e^(-x^2) is 1/e^a, then a = ?
*Wednesday, December 10, 2014 by JOE*

**Calculus**

This is a calculus homework question but in reality the problem here is understanding the algebra. Find the Critical Numbers of f(x) = x^(3/5)(4-x) The product rule gives -x^(3/5) + (12-3x)/(5x^(2/5) My booklet explains that simplifying this gives you 12-8x / (5x^(2/5). How ...
*Wednesday, December 10, 2014 by David*

**College Algebra**

According to Newton's law of cooling, the rate at which an object cools is directly proportional to the difference in temperature between the object and the surrounding medium. The face of a household iron cools from 130° to 100° in 30 minutes in a room that ...
*Wednesday, December 10, 2014 by Kyle *

**Calculus**

A deposit of $5,000 at 4% interest compounded continuously will grow to V(t) = 5000e^0.04t dollars after t years. Find the average value during the first 20 years (that is, from time 0 to time 20). (Round your answer to the nearest cent.)
*Wednesday, December 10, 2014 by Madison*

**calculus**

The position, in feet, of a target is given by s(t)=250-3t+9t^2+2t^3, where t is the time in seconds. The origin of coordinates is at the point where an observer stands, and the positive direction of movement is that one pointing EAST from the origin. What is the initial ...
*Tuesday, December 9, 2014 by Jane*

**Calculus angle of elevation**

A man is walking towards a wall at 3 ft/sec while looking at a picture on the wall, at a height of 5 feet from the floor. How is the angle of observation changing when the man is 8 feet away from the screen.
*Tuesday, December 9, 2014 by Jane*

**Calculus- Tangent Line**

What is the slope of the tangent line to the curve at the point (4, 0)? Okay, so I got 0.5, did I do this right?
*Tuesday, December 9, 2014 by Harry*

**Euler's method help in Calculus?????**

Let dy/dx=xy . Use Euler's method with step size of 0.5 and the initial condition of y(0) = 3 to estimate y(2). I really am not sure if I did this right, but I got 3.4568 for y(2). I actually feel like it is wrong.
*Tuesday, December 9, 2014 by Jane*

**Calculus**

Y=2sinx-cos^2(x) F"(x)=-sinx+cos^2-sin^2(x) Find the points of inflection and concavities
*Tuesday, December 9, 2014 by Anonymous*

**Calculus**

Find the equation of the tangent line to the hyperbola 3x^2-4y^2=8 which is/are perpendicular to the line 2x-3y+6=0. Give the answers in general form.
*Tuesday, December 9, 2014 by Diolo*

**Calculus**

lim (e^x+3x)^1/x as x approaches 0
*Tuesday, December 9, 2014 by Diolo*

**Calculus**

Y=2sinx-cos^2(x) on [0, 2pi] How do you solve for the x-intercept
*Tuesday, December 9, 2014 by Anonymous*

**General Calculus Question**

How do you solve a limit when it approaches infinity and there is a square root in the denominator? say the highest power is x^2 in both the numerator and denominator.
*Monday, December 8, 2014 by Anonymous*

**AP Calculus**

For the function y=4-2x^2+1/6x^4 find the following: Domain x and y intercepts Vertical asymptotes Horizontal asymptotes Symmetry F'(x) Critical numbers Increasing f(x) Decreasing f(x) Extrema F"(x) Possible points of inflection Concave up Concave down Points of ...
*Monday, December 8, 2014 by Sarah*

**Calculus**

A particle moves along line segments from the origin to the points (3, 0, 0), (3, 3, 1), (0, 3, 1), and back to the origin under the influence of the force field F(x, y, z) = z2i + 5xyj + 4y2k. I have tried multiple times to solve this problem but the answer is still not right.
*Monday, December 8, 2014 by Katie*

**Calculus**

Find critical points for y'=2/3x^3-4x
*Monday, December 8, 2014 by Anon*

**Calculus **

A particle moves along line segments from the origin to the points (3, 0, 0), (3, 3, 1), (0, 3, 1), and back to the origin under the influence of the force field F(x, y, z) = z2i + 5xyj + 4y2k. I have tried multiple times to solve this problem but the answer is still not right.
*Monday, December 8, 2014 by Jessica*

**Calculus**

So this one is confusing me: limit of n as it approaches infinity of (n{SIGMA}i=1) (1/(2^i) *the n is on top of the sigma notation and i=1 is at the bottom. I understand that 'i' would equal (n(n+1))/2 however the algebra from there confuses me.
*Monday, December 8, 2014 by David*

**calculus**

A rectangular fence has to be built from both wood and metal so that opposite parallel sides of the fence are made from the same type of material. The wood costs $10 per foot and the metal costs $20 per foot of the fence used. If you only have $400 to spend on material, what ...
*Monday, December 8, 2014 by Paige *

**Calculus**

I am trying to solve the following L'hopital's limits question below: lim x -> 0 from the positive direction of ( 5^(sin(x)) - 1 )/ (x)
*Monday, December 8, 2014 by David*

**calculus**

Previously asked: the length of a rectangular prism is increasing at a rate of 8 cm/s, its width is increasing at a rate of 3 cm/s, and its height is increasing at a rate of 5 cm/s. when the length is 20 cm, width is 10 cm, and height is 15 cm, how fast is the volume of the ...
*Sunday, December 7, 2014 by Dani*

**calculus**

First, the bond pays 96 + 7 t per year for 10 years. Second, the interest rate is 5.25% compounded continuously. Round your answer to the nearest cent. Find the present value?
*Sunday, December 7, 2014 by Dat nguyen*

**Calculus**

Find the area of the region bounded by the curves y=12-x^2 and y=x^2-6. Hint:The answer should be a whole number.
*Sunday, December 7, 2014 by Bill*

**Calculus**

L'hopital's question below: lim x -> 0 from the positive direction of ( 5^(sin(x)) - 1 )/ (x)
*Sunday, December 7, 2014 by David*

**Math - Calculus**

If 75100 dollars is deposited in an account for 13 years at 5.35 percent compounded continuously , find the average value of the account during the 13 years period. The average value in the account is ? ** im alittle confused in how to find the average value please help and ...
*Sunday, December 7, 2014 by Anonymous*

**Calculus**

Find the average value of the function f(x) 8x^2-9x+8 on the interval [3,5]. Find the value of the x-coordinate at which the function assumes it's average value The average value is ? the x-coordinate is ? Please help and showing work is much appreciated. Thank you
*Sunday, December 7, 2014 by Anonymous*

**Calculus**

Lines tangent to the curve y-1=2x^2+3x pass through the point A(2,-1). Find the x-coordinate(s) of the point(s) of tangency. The answer is 2+2^1/2, 2-2^1/2, I just don't know how to get there. Please help! Thank you!
*Sunday, December 7, 2014 by Ty*

**Pre calculus**

at an archaeological site remains of plant material will found to have 28.9% of the amount of carbon-14 in a living sample. What was the approximate age of the plant material?
*Saturday, December 6, 2014 by crisly*

**calculus**

the length of a rectangular prism is increasing at a rate of 8 cm/s, its width is increasing at a rate of 3 cm/s, and its height is increasing at a rate of 5 cm/s. when the length is 20 cm, width is 10 cm, and height is 15 cm, how fast is the volume of the rectangular prism ...
*Saturday, December 6, 2014 by Dani*

**calculus**

definite integral of (e^(8x))cosh(8x)dx from 0 to 1/16 -I substitued the definition of cosh in, i.e. (e^(8x) + e^(-8x)/2 but i cant get the "e's" to combine and i know the answer is e/32
*Saturday, December 6, 2014 by gregory*

**Pre Calculus**

You have been hired by the Humane Society to construct six 2 by 3 animal cages using 1400 feet of chain fence. Express the length and width using function notation. Include a graph with the area function with explanation of significance. Find the dimensions that maximize the ...
*Friday, December 5, 2014 by Guillermo*