Monday

April 21, 2014

April 21, 2014

**Recent Homework Questions About Calculus**

Post a New Question | Current Questions

**calculus help**

I've tried your answers to this question but they were all marked wrong. Thanks anyway!
*Saturday, April 19, 2014 at 5:57pm*

**Calculus Help**

I did put these answers in but they're marked wrong Thank you!
*Saturday, April 19, 2014 at 5:41pm*

**calculus help**

Nothing. I use SCI unless ordered otherwise :)
*Saturday, April 19, 2014 at 5:11pm*

**calculus help**

what's wrong with 28/3 mi/hr/s ? :-)
*Saturday, April 19, 2014 at 5:04pm*

**calculus help**

4.14 m/s^2 = 13.6 ft/s^2 :)
*Saturday, April 19, 2014 at 4:55pm*

**calculus help**

ignore the very last "the acceleration is 9.33" pressed "post answer" too soon so the acceleration is a = 13.59 ft/s^2 and v = 13.59t + 32.2667 a = 13.59 ft/s^2
*Saturday, April 19, 2014 at 4:52pm*

**Calculus Help**

b) the answer is in (a) twice 2178 feet I think you can figure the rest out
*Saturday, April 19, 2014 at 4:45pm*

**calculus help**

If the acceleration is a then v = at + c , where c is a constant: when t=0 , v = 22 mi/h = 32.2666.. ft/s 32.266.. = a(0) + c c = 32.2666.. when t = 3s , v = 50 mi/h = 73.333.. ft/s 73.333.. = a(3) + 32.26666... 3a = 41.06666.. a = 13.58888.. the acceleration is 13.89 ft/s^2 ...
*Saturday, April 19, 2014 at 4:44pm*

**Calculus Help**

90 mi/hr = 132 ft/s (a) first how long and how far to reach 132 ft/s v = 0 + 4 t 132 = 4 t t = 33 s to reach 132 d = .5 a t^2 = 2 (33)^2 = 2178 ft to reach cruising speed 15*60 = 900 seconds total 900 - 33 = 867 seconds left how far at cruising speed 132 ft/s * 867 s = 114,...
*Saturday, April 19, 2014 at 4:43pm*

**calculus help**

22 mph = 9.83 m/s 50 mph = 22.35 m/s a = change in velocity/time = (22.35 -9.81)/3 = 4.18 m/s^2 or about half g
*Saturday, April 19, 2014 at 4:32pm*

**Calculus Help **

A high-speed bullet train accelerates and decelerates at the rate of 4 ft/s2. Its maximum cruising speed is 90 mi/h. (Round your answers to three decimal places.) (a) What is the maximum distance the train can travel if it accelerates from rest until it reaches its cruising ...
*Saturday, April 19, 2014 at 3:55pm*

**calculus help**

What constant acceleration is required to increase the speed of a car from 22 mi/h to 50 mi/h in 3 s? (Round your answer to two decimal places.)
*Saturday, April 19, 2014 at 3:42pm*

**calculus**

x^2+1=0 x^2=-1 in real numbers it cant be. so x=i and x=-i (solution in the set of complex numbers)
*Saturday, April 19, 2014 at 9:09am*

**calculus**

x^4 + 2x^2 + 1 = 0 (x^2)^2 +2x^2 +1 = 0 (x^2 + 1)^2 = 0 I don't know where to go now although I know the answer is x = i, -i
*Saturday, April 19, 2014 at 9:03am*

**Calculus Help Please Urgent!!!**

I stand by mine and Damon's answer for a minimum area. I even ran a simple 1980's style "BASIC" program to show it 10 a = 5000 20 for x = 0 to 14 step 1.000000E-05 30 y = (14-4*x)/3 40 na = x*x+sqr(3)/4*y*y 50 if na < a then a = na : side = x 60 next x 70 ...
*Saturday, April 19, 2014 at 8:24am*

**Calculus Please Need Urgent3 :/**

see what I said here: http://www.jiskha.com/display.cgi?id=1397810241
*Saturday, April 19, 2014 at 4:54am*

**Calculus Please Need Urgent2 :/**

what, no ideas at all? Just straightforward integration. f"(x) = 8x+4sin x f'(x) = 4x^2 - 4cos x + C So, since f'(0) = 2, 16-4+C = 2 C = -10 and so f'(x) = 4x^2 - 4cos x - 10 Now do that all over again to get f(x)
*Saturday, April 19, 2014 at 4:52am*

**Calculus Please Need Urgent :/**

you have ∫-8e^x - 6sec^2 x dx = -8e^x - 6tan x + C
*Saturday, April 19, 2014 at 4:50am*

**Calculus Help Please!**

what's the problem? The integral is just normal power stuff ∫ t^3 + 6t^2 + 4 dt = 1/4 t^4 + 2t^3 + 4t now evaluate that at x and 0, and you have f(x) = 1/4 x^4 + 2x^3 + 4x so, f"(x) = 3x^2 + 12x
*Saturday, April 19, 2014 at 4:48am*

**calculus - garbled**

better try just typing in the text, rather than copying from you application.
*Saturday, April 19, 2014 at 4:45am*

**calculus**

Let f x coth x . Use the Graph software posted in Moodle to do the following: (a) Graph f x . (b) Graph the tangent and normal lines to the graph of f x at x 1. (c) Graph f x . (d) ...
*Saturday, April 19, 2014 at 3:19am*

**Calculus Please Need Urgent3 :/**

Find the derivative of the following function using the appropriate form of the Fundamental Theorem of Calculus. F(x)= (s^2)/(1+3s^4)ds from sqrtx to 1 F'(x)=? Thank you so much guys!
*Saturday, April 19, 2014 at 12:39am*

**Calculus Please Need Urgent2 :/**

Consider the function f(x) whose second derivative is f''(x)=8x+4sin(x). If f(0)=3 and f'(0)=2, what is f(x)? f(x)=??
*Saturday, April 19, 2014 at 12:38am*

**Calculus Please Need Urgent :/**

Find the most general antiderivative of f(x)=–8e^x–6secant^2(x) where -pi/2<x<pi/2 Note: Any arbitrary constants used must be an upper-case "C". F(x)=?
*Saturday, April 19, 2014 at 12:37am*

**Calculus Help Please!**

If f(x)=Integral (t^3+6t^2+4)dt from 0 to x then f''(x)=?
*Saturday, April 19, 2014 at 12:34am*

**Calculus Help and Check**

v = 3/2 √t s = t^(3/2)+C 8+C = 17, so C=9 s(t) = t^(3/2) + 9 How did you get C=1?
*Saturday, April 19, 2014 at 12:24am*

**Calculus Help Please Urgent!!!**

How about this then? if the side of the square is x and the side of the triangle is y, then 4x + 3y = 14 and the total area is x^2 + y^2 √3/4 = x^2 + √3/4 (14-4x)/3)^2 = 1/18 (18x^2 - 2√3 x + 7√3) just a parabola, with vertex at x = 1/(6√3) So, ...
*Saturday, April 19, 2014 at 12:19am*

**Calculus Help and Check**

how about the third one!
*Friday, April 18, 2014 at 11:56pm*

**Calculus Help and Check**

first: correct, also x/5)- ln(x^3)+C second 2x^2+x^3+3x^4+8x+Cx + K f(o)=2=k or K=2 f(1)=10=2+1+3+8+C +2 means C=10-16=-6 >>>f(x)=2x^2+x^3+3x^4+8x -6x + 2 f'= 4x + 3x^2 +12x^3 + 2 f"= 4+6x + 36x^2
*Friday, April 18, 2014 at 11:00pm*

**Calculus Help and Check**

1)Find the most general antiderivative of the function. (Check your answer by differentiation. Use C for the constant of the antiderivative. Remember to use ln |u| where appropriate.) f(x) = (1/5)−(3/x) -----> (x/5)-3lnx+C 2)Find f. f ''(x) = 4 + 6x + ...
*Friday, April 18, 2014 at 10:47pm*

**Calculus Help Please Urgent!!!**

Thank you both! But your answers were wrong.
*Friday, April 18, 2014 at 10:40pm*

**Calculus Help Please Urgent!!!**

I also got 6.09 (actually 6.0895..) I defined the side of the triangle slightly different from Damon to avoid as many fractions as I could. let each side of the square be x m let each side of the equilateral triangle be 2y m that way I can say that the height of the triangle ...
*Friday, April 18, 2014 at 8:20pm*

**Calculus Help Please Urgent!!!**

square side = x triangle side = y perimeter = 4 x + 3 y = 14 area = x^2 + sqrt3 (y^2)/4 x = (14 - 3 y)/4 area = (196 - 84 y +9y^2)/16 + 4 (3^.5)y^2/16 = [1/16] (196 - 84 y + 15.93 y^2) dA/dy = 0 for max or min 0= -84 y + 31.86 y^2 so y = 0 or y = 2.63 so x = 14/4 or 1.528 so 4...
*Friday, April 18, 2014 at 8:02pm*

**Calculus Help Please Urgent!!!**

A piece of wire 14 m long is cut into two pieces. One piece is bent into a square and the other is bent into an equilateral triangle. (a) How much wire should be used for the square in order to maximize the total area? 14 m this one I got right (b) How much wire should be used...
*Friday, April 18, 2014 at 6:57pm*

**calculus**

your equation came out looking rather jibberish on my computer, but I see it contans x's and y's I can give you the general method of doing this question .... Find the derivative with respect to t, then your result should contain dx/dt and dy/dt , as well as x and y ...
*Friday, April 18, 2014 at 8:23am*

**calculus**

when the man is x from the pole, and his shadow is s, 150/300 = h/(250+300) so, the pole's height is h=275 cm so, at any time, 150/s = 275/(x+s) or, more easily manipulated, (x+s)/275 = s/150 x/275 = s/330 x = 5/6 s so, at any time dx/dt = 5/6 ds/dt since dx/dt = 15, ds/dt...
*Friday, April 18, 2014 at 5:39am*

**Calc**

Find the derivative of the following function using the appropriate form of the Fundamental Theorem of Calculus. intergral s^2/(1+3s^4) ds from sqrtx to 1 F'(x)=?
*Friday, April 18, 2014 at 4:37am*

**Calculus**

Consider the function f(x) whose second derivative is f''(x)=8x+4sin(x). If f(0)=3 and f'(0)=2, what is f(x)?
*Friday, April 18, 2014 at 4:35am*

**Calculus**

Find the derivative of the following function using the appropriate form of the Fundamental Theorem of Calculus. intergral s^2/(1+3s^4) ds from sqrtx to 1 F'(x)=?
*Friday, April 18, 2014 at 4:34am*

**calculus**

A bug crawls along the graph of 2 y x x 4 1 , where x and y are positive and measured in centimeters. If the x-coordinate of the bug’s position x y, changes at a constant rate of 3 cm/min, how fast is the y-coordinate changing ...
*Friday, April 18, 2014 at 3:48am*

**calculus **

A person 150cm tall is walking away from a lamp post at the rate of 15 meter per minute. when the man is 2.5m from the lamp post, his shadow is 3m long. Find the rate at which the length of the shadow is increasing when he is 7m from the lamp post.
*Friday, April 18, 2014 at 1:09am*

**calculus**

1
*Thursday, April 17, 2014 at 10:45pm*

**Calculus**

g' = 8f + 8x * f' g'(3) = 8f(3) + 24*f'(3) = 8*4 + 24*5 = 152
*Thursday, April 17, 2014 at 1:22pm*

**Calculus**

Given f(3)=4 and f'(3)=5, find g'(3), where g(x)=8x.f(x)
*Thursday, April 17, 2014 at 1:17pm*

**CALCULUS**

with a slight change to the numbers, this question is treated at http://www.jiskha.com/display.cgi?id=1392927547
*Thursday, April 17, 2014 at 12:08pm*

**Calculus**

let be base be x ft by x ft let the height be y ft (x^2)(y) = 3 y = 3/x^2 Cost = 3(x^2) + 2(4xy) = 3x^2 + 8x(3/x^2) = 3x^2 + 24/x d(cost)/dx = 6x - 24/x^2 = 0 for a min of cost 6x = 24/x^2 x^3 = 4 x = cuberoot(4) = appr 1.6 ft the base should be appr 1.6 ft by 1.6 ft (the ...
*Thursday, April 17, 2014 at 9:25am*

**Calculus**

An open top box with a square base is to be made so that it holds 3 cubic feet. Assuming the material on the base costs $3 per square foot and the material on the sides costs $2 per square foot, determine the size of the base that minimizes the total cost.
*Wednesday, April 16, 2014 at 11:09pm*

**CALCULUS **

The base of S is a circular disk with radius 3r. Parallel cross-sections perpendicular to the base are isosceles triangles with height 8h and unequal side in the base. a. set up an interval for volume of S b. by interpreting the intergal as an area, find the volume of S
*Wednesday, April 16, 2014 at 9:49pm*

**calculus help**

https://www.wolframalpha.com/input/?i=derivative+of+x^2%28x%2B3%29%2F%28x%2B1%29^3 6x / (x+1)^4
*Wednesday, April 16, 2014 at 7:21pm*

**calculus help**

then do it again :)
*Wednesday, April 16, 2014 at 7:19pm*

**calculus help**

[(x+1)^2 (3 x^2)-x^3 (2)(x+1)] /(x+1)^4 [(x+1)(3x^2) - 2 x^3 ]/ (x+1)^3 [ 3 x^3 + 3 x^2 -2 x^3 ] / (x+1)^3 [ x^3 + 3 x^2] /(x+1)^3 x^2 (x+3) / (x+1)^3
*Wednesday, April 16, 2014 at 7:15pm*

**calculus help**

https://www.wolframalpha.com/input/?i=derivative+of+%28x^3%29%2F%28%28x%2B1%29^2%29+
*Wednesday, April 16, 2014 at 7:09pm*

**calculus help**

find y' and y'' for the equation below. Show work please!!! y= (x^3)/((x+1)^2)
*Wednesday, April 16, 2014 at 6:53pm*

**calculus**

http://www.mathsisfun.com/data/function-grapher.php f' = 7 e^7x - e^-x when is that zero? 7 e^7x = e^-x 7 e^8x = 1 e^8x = 1/7 8 x = ln(1/7) x = -.243 at min
*Wednesday, April 16, 2014 at 6:12pm*

**calculus help**

try : https://www.google.com/search?q=graph+ln%28x%29+from+1+to+6&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a&channel=sb ln 6 = 1.79 ln 1 = 0 ln 6 - ln 1 = 1.79 1.79/5 = .36 approx ln x = .36 e^ln x = ? = e^.36 so x = 1.43 sure ...
*Wednesday, April 16, 2014 at 5:54pm*

**calculus help**

Play with this: https://www.wolframalpha.com/input/?i=derivative+of+1%2B%281%2Fx%29%2B%285%2Fx^2%29%2B%281%2Fx^3%29+
*Wednesday, April 16, 2014 at 5:45pm*

**calculus help check and help**

a) calculate lim t->infinity (v. answer: mg/c ----->what is the meaning of this limit ============================== It is the "terminal velocity" (Google that) which is the speed where the drag force equals the weight. One uses a parachute so that one's ...
*Wednesday, April 16, 2014 at 5:39pm*

**calculus help**

Produce graphs of f that reveal all the important aspects of the curve. Then use calculus to find the intervals of increase and decrease and the intervals of concavity. f(x)= 1+(1/x)+(5/x^2)+(1/x^3) find the interval of increase. find the interval of decrease. find the ...
*Wednesday, April 16, 2014 at 5:37pm*

**calculus help check and help **

if an object with mass m is dropped from rest, one model for its speed v after t seconds, taking air resistance into account is v= mg/c(1-e^(-ct/m)) where g is the acceleration due to gravity and c is a positive constant describing air resistance. a) calculate lim t->...
*Wednesday, April 16, 2014 at 5:01pm*

**calculus **

consider the equation below f(x)=e^(7x)+e^(-x) find the intervals on which f is increasing and decreasing (enter your answers using interval notation) find the local minimum of f. find the interval on which f is concave up.
*Wednesday, April 16, 2014 at 4:24pm*

**calculus help**

Does the function satisfy the hypotheses of the Mean Value Theorem on the given interval? f(x)= ln(x) , [1,6] If it satisfies the hypotheses, find all numbers c that satisfy the conclusion of the Mean Value Theorem. (Enter your answers as a comma-separated list. If it does not...
*Wednesday, April 16, 2014 at 4:15pm*

**Calculus Help Please!!!**

As mentioned, let BC = x distance over water: √(x^2+49) distance over land: 11-x (a) energy expended: y = 1.3√(x^2+49) + 11-x dy/dx = 1.3x/√(x^2+49) - 1 y'=0 at x = 70/√69 what do you get for the other parts?
*Wednesday, April 16, 2014 at 3:54pm*

**calculus help**

There's a nice discussion here: http://math.stackexchange.com/questions/126755/lhospitals-rule-with-indeterminate-powers
*Wednesday, April 16, 2014 at 3:44pm*

**calculus help**

explain fully what trick you must use in order to us L'Hospital's rule for indeterminate powers?
*Wednesday, April 16, 2014 at 3:33pm*

**Calculus Help!!!!!**

should be no problem. That's just Algebra II. Anyway, y = x^3/(x+1)^2 y' = x^2(x+3)/(x+1)^3 y" = 6x/(x+1)^4 see the graph and some analysis here: http://www.wolframalpha.com/input/?i=x^3%2F%28x%2B1%29^2
*Wednesday, April 16, 2014 at 3:29pm*

**Calculus Help!!!!!**

sketch the graph of the following. Show all your work and include all the important points and asymptotes. also find y' and y'' ? y= (x^3)/(x+1)^2
*Wednesday, April 16, 2014 at 3:21pm*

**Calculus Help Please!!!**

Ornithologists have determined that some species of birds tend to avoid flights over large bodies of water during daylight hours. It is believed that more energy is required to fly over water than land because air generally rises over land and falls over water during the day. ...
*Wednesday, April 16, 2014 at 2:26pm*

**Calculus Help Please Urgent!!!**

1/3 pi r^2 h = 30, so h = 90/(pi r^2) surface area = 2 pi r s where r^2+h^2 = s^2, so a = 2 pi r √(r^2 + (90/(pi r^2))^2) = 2/r √(pi^2 r^6 + 8100) for minimum paper, we need da/dr = 0, so, as wolframalpha so ably shows at http://www.wolframalpha.com/input/?i=2+p&#...
*Wednesday, April 16, 2014 at 6:06am*

**calculus help please**

let each side of the square be x m let each side of the equilateral triangle be 2x (that way, the height is √3y, from the ratio of the 30-60-90° triangle) a) for a max area, you are right, all should be used for the square b) 4x + 6y = 14 2x + 3y = 7 x = (7-3y)/4 OR ...
*Tuesday, April 15, 2014 at 11:41pm*

**calculus help**

R(x)=x(1800-6x) R(x)=1800x-6x^2 R'(x)=1800-12x C'(x)=600-1.2x+.012x^2 Marginal revenue = marginal cost 1800-12x=600-1.2x+.012x^2 1200=10.8x+.012x^2 1200=.012x(900+x) 100,000=x(900+x) 100,000=900x+x^2 x^2+900x-100000 =0 (x-100)(x-1000) =0 x = 100 x+1000) = 0 x = 100 At ...
*Tuesday, April 15, 2014 at 10:33pm*

**calculus help please **

A piece of wire 14 m long is cut into two pieces. One piece is bent into a square and the other is bent into an equilateral triangle. (a) How much wire should be used for the square in order to maximize the total area? = 14 m (b) How much wire should be used for the square in ...
*Tuesday, April 15, 2014 at 10:10pm*

**calculus help**

If C(x) = 12000 + 600x − 0.6x^2 + 0.004x^3 is the cost function and p(x) = 1800 − 6x is the demand function, find the production level that will maximize profit. (Hint: If the profit is maximized, then the marginal revenue equals the marginal cost.)
*Tuesday, April 15, 2014 at 8:35pm*

**Calculus Help Please Urgent!!!**

A cone-shaped paper drinking cup is to be made to hold 30 cm^3 of water. Find the height and radius of the cup that will use the smallest amount of paper. (Round your answers to two decimal places.) Height = ? Radius = ? Show work please!!!
*Tuesday, April 15, 2014 at 8:06pm*

**Math--Calculus**

Hmm. Don't know...
*Tuesday, April 15, 2014 at 1:42pm*

**Calculus II**

Compute the first 5 terms of the sequence: {b(n)}n=1-> infinity = nsqrt(6n) + (5/6)^n. ((that is:(Bsub(n))from n=1 to infinity = nth root of 6n + (5/6)raised to n.)) If the sequence converges, find the limit.
*Tuesday, April 15, 2014 at 1:08pm*

**Calculus II**

Consider the sequence: (a,sub(n))={1/n E(k=1 to n) 1/1+(k/n)} Show that the limit(as n-> infinity) A(sub(n))= ln 2 by interpreting a(sub(n)) as a Reimann Sum of a Definite Integral.
*Tuesday, April 15, 2014 at 1:07pm*

**calculus**

1/10 ∫[0,10] 3/(x+1) dx = 3/10 ln(11)
*Tuesday, April 15, 2014 at 5:05am*

**calculus**

find average value of f [0,10] f(x)= 3/x+1
*Tuesday, April 15, 2014 at 12:47am*

**calculus**

So, the height is 40/x^2 c(x) = 2x^2*5 + 4x(40/x^2)*2 = 10x^2 + 320/x set the derivative to zero, and you find minimum cost at x = 2∛2
*Tuesday, April 15, 2014 at 12:11am*

**calculus**

A box is contructed out of two different types of metal. The metal for the top and bottom, which are both square, costs $5 per square foot and the metal for the sides costs $2 per square foot. Find the dimensions that minimize cost if the box has a volume of 40 cubic feet.
*Monday, April 14, 2014 at 11:41pm*

**calculus**

false
*Monday, April 14, 2014 at 11:09pm*

**Calculus II**

Compute the first 5 terms of the sequence: {b(n)}n=1¨‡ = nã6n + (5/6)^n. ((that is:(Bsub(n))from n=1 to infinity = nth root of 6n + (5/6)raised to n.)) If the sequence converges, find the limit.
*Monday, April 14, 2014 at 5:44pm*

**Calculus 2**

In the following series x is a real number. In each case, use the ratio test to determine the radius of convergence of the series. Analyze the behavior at the endpoints in order to determine the interval of convergence. a. Summation n=0 to infinity (n(x^n))/(n^2 + 2) b. ...
*Monday, April 14, 2014 at 2:55pm*

**Calculus Help Please Urgent!!!**

Hmmm. we all know that tan x -> x as x->0 so, cot x -> 1/x as x->0 so the limit ought to be zero.
*Sunday, April 13, 2014 at 11:33pm*

**Calculus Help Please Urgent!!!**

lim -> 0 (cot(x)-(1/x)) , x---> 0 = sec^2 x + 1/x^2 by L'Hospital's Rule but that is just as bad try experimentally ... using a Calculator let x = .0001 I get -.0000333 let x = .000001 my calculator says 0 http://www.wolframalpha.com/input/?i=limit+cot%28x...
*Sunday, April 13, 2014 at 11:06pm*

**Calculus Help Please Urgent!!!**

find the limit algebraically. Use L'Hospital's Rule where appropriate. If there is a moare elementary method, consider using it. If L'Hospital's Rule doesn't apply, explain why lim -> 0 (cot(x)-(1/x)) show work please!!!
*Sunday, April 13, 2014 at 10:39pm*

**Calculus**

let the length of the side using bricks be x ft let the other two sides each be y ft given: xy = 900 --> y = 900/x cost = 5(x + 2y) + 10x = 15x + 10y = 15x + 10(900/x) d(cost)/dx = 15 - 9000/x^2 = 0 for min of cost 15 = 9000/x^2 15x^2 = 9000 x^2 = 600 x = √600 = 10&#...
*Sunday, April 13, 2014 at 10:03pm*

**Calculus**

ABC Daycare wants to build a fence to enclose a rectangular playground. The area of the playground is 900 square feet. The fence along three of the sides costs $5 per foot and the fence along the fourth side, which will be made of brick, costs $10 per foot. Find the length of ...
*Sunday, April 13, 2014 at 9:48pm*

**Math 10**

sure, all you have to do is to find the vertex of this "downwards" parabola. I will assume that you do not know Calculus , so (easiest way): the x of the vertex for y = ax^2 + bx + c is -b/(2a) so for your equation, the t of the vertex is -10/-10 = 1 sub into the ...
*Sunday, April 13, 2014 at 6:57pm*

**calculus**

if the printed area has width and height x and y, then the total area is a = (x+8)(y+12) and xy=384 a = (x+8)(384/x + 12) = 12x + 3072/x + 480 that is minimum when da/dx = 0, so we need 12 - 3072/x^2 = 0 x = 16 so the poster is (16+8) by (24+6) or 24x30
*Sunday, April 13, 2014 at 6:48am*

**calculus**

Hmmm. If the population is p, then we have dp/dt = kp dp/p = k dt ln(p) = kt + c p = c e^kt Now we know that p triples in 14 days, so we can forgo using e, and just use 3 as our base: p(t) = Po * 3^(t/14) so, starting with 100, and gaining 15 per day and losing 23 each day, ...
*Sunday, April 13, 2014 at 6:42am*

**calculus**

A population of a very rare insect in an area in a discrete rural region in ASEAN will grow at a rate that is proportional to their current population. In the absence of any outside factors, the population will triple in two weeks’ time. On any given day there is a net ...
*Sunday, April 13, 2014 at 12:19am*

**calculus**

The top and bottom margins of a rectangular poster are 6 centimeters each, and the side margins are 4 centimeters each. If the area printed on the poster is fixed at 384 cm2, a) Sketch the figure. b) Find the dimensions of the poster using the least amount of paper.
*Sunday, April 13, 2014 at 12:17am*

**calculus**

in the following series x is a real number. In each case use the ratio test to determine the radius of convergence of the series. Analyze the behavior of the series at the endpoints in order to determine the interval of convergence. A) (nx^n)/(n^2 + 2) B)((n^2)(x-2)^n)/2^n C...
*Saturday, April 12, 2014 at 9:18pm*

**CALCULUS**

algebraically, since both functions are symmetric about the origin, the area is zero. geometrically, using symmetry, you have the area is 2∫[0,pi/9] (tan3x - 2sin3x) dx = 2/3 (2cos 3x - log cos 3x)[0,pi/9] = 2/3 (log2 - 1)
*Saturday, April 12, 2014 at 6:37pm*

**Calculus**

y = xe^(-4x) y' = (1-4x)e^(-4x) y" = 8(2x-1)e^(-4x) since e^(-4x) > 0 for all x, y" < 0 when 2x-1 < 0. see the graph at http://www.wolframalpha.com/input/?i=+xe^%28-4x%29+for+0+%3C%3D+x+%3C%3D+1
*Saturday, April 12, 2014 at 6:27pm*

**CALCULUS**

or thats not right
*Saturday, April 12, 2014 at 5:30pm*

**CALCULUS**

thank you!
*Saturday, April 12, 2014 at 5:27pm*

**Calculus**

For what values of x is the graph of y=x e^{-4 x} concave down?
*Saturday, April 12, 2014 at 5:07pm*

**CALCULUS**

If I read it correctly, you have y=4/x, y=16x, and y=x/16 for x>0 You need to break the area into two regions, because the two top curves intersect at x = 1/2 So the area is ∫[0,1/2] 16x - x/16 dx + ∫[1/2,8] 4/x - x/16 dx = (8x^2-x^2/32)[0,1/2] + (4logx-x^2/32)[...
*Saturday, April 12, 2014 at 4:47pm*

Pages: **1** | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | Next>>

Post a New Question | Current Questions