Tuesday

July 7, 2015

July 7, 2015

**pre - CALCULUS**

Verify the identity. Show your work. cot θ ∙ sec θ = csc θ
*Thursday, April 9, 2015 by Ciara*

**Calculus**

During a certain epidemic, the number of people that are infected at any time increases at rate proportional to the number of people that are infected at that time. 1,000 people are infected when the epidemic is first discovered, and 1,200 are infected 7 days later. Write and ...
*Thursday, April 9, 2015 by Anonymous*

**Calculus**

The number of people that hear a rumor follows logistic growth. In a school of 1500 students, 5 students start a rumor. After 2 hours, 120 students have heard about the rumor. Recall: dy/dx=ky(1-Y/L) and y=L/(1+be^(-kt)) I found the logistic growth equation to be 1500/(1+299e...
*Thursday, April 9, 2015 by Anonymous*

**Calculus**

Find the particular solution (solved for y) for the differential equation dy/dx=2x/e^(2y) satisfying y(0)=1.
*Thursday, April 9, 2015 by Anonymous*

**Calculus**

A manufacturer has determined that the weekly profit from the sale of x items is given by the function below. It is estimated that after t days in an week, x items will have been produced. Find the rate of change of profit with respect to time at the end of 7 days. P9x) = -x^2...
*Thursday, April 9, 2015 by Stacey *

**CALCULUS **

Consider the function f(x)=9x3−4x5. Let F(x) be the antiderivative of f(x) with F(1)=0. Then F(4) =
*Thursday, April 9, 2015 by Anonymous*

**Calculus**

Suppose that y=f(x) = sqrt(2x), x>=0 Find a c > 0 such that the tangent line to the curve y = f(x) at x = c has the same slope as the tangent line to the curve y = f^–1(x) at x = c. You get: c = 1/8 c = 1/2 c = (1/8)^(1/3) c = (1/3)^(2/3) c = (1/2)^(1/3)
*Thursday, April 9, 2015 by Thomas*

**Calculus AB**

For the function f(x) = sqrt(9-x), which is equal to d/dx(f-1( -1 is the inverse)(x)) a) -2x b) sqrt(x) + 9 c) x^2 + 9 d) 2x e) 9-x^2
*Thursday, April 9, 2015 by Thomas*

**Calculus**

For the function f(x) = x^2 - 4x +5, x>= 2, which is equal to d/dx (f-1 this is the inverse)(x)) ? 1/(2y-4) where x and y are related by the equation (satisfy the equation) x=y^2-4y+5 x>= 1 2y-4 where x and y are related by the equation y= = x^2 - 4x +5, x>= 2 1/2x-4 ...
*Thursday, April 9, 2015 by Thomas*

**Calc AB**

Remember that f(x) must be one-to-one (only one y-value for each x-value) over the domain where f –1(x)is defined as a function. So, in some cases you must restrict the domain of f(x) so that it's one-to-one. There might be more than one section of domain that's ...
*Thursday, April 9, 2015 by Thomas*

**Calculus**

Batman was driving the Batmobile at 90 mph (=132 ft/sec), when he sees a brick wall directly ahead. When the Batmobile is 400 feet from the wall, he slams on the brakes, decelerating at a constant rate of 22ft/sec2. Does he stop before he hits the brick wall? If so, how many ...
*Thursday, April 9, 2015 by Meme *

**Calculus**

A rectangular storage container with an open top is to have a volume of k cubic meters. The length of its base is twice its width. The material for the base costs $6 per square meters and the material for the sides costs $10 per square meter.
*Thursday, April 9, 2015 by Joseph*

**Calculus**

In a poll of 400 voters in a certain state, 61% said that they opposed a voter ID bill that might hinder some legitimate voters from voting. The margin of error in the poll was reported as 4 percentage points (with a 95% degree of confidence). Which statement is correct? A. ...
*Thursday, April 9, 2015 by Scott*

**Calculus**

Joe dealt 20 cards from a standard 52-card deck, and the number of red cards exceeded the number of black cards by 8. He reshuffled the cards and dealt 30 cards. This time, the number of red cards exceeded the number of black cards by 10. Determine which deal is closer to the ...
*Thursday, April 9, 2015 by Scott*

**calculus (please with steps and explanations)**

consider the function f that is continuous on the interval [-5,5] and for which the definite integral 0(bottom of integral sign) to 5(top of integral sign) of f(x)dx=4. Use the properties of the definite integral to evaluate each integral: (a) definite integral from 0(on the ...
*Thursday, April 9, 2015 by Linda*

**Calculus**

The sun is setting at the rate of 1/4 deg/min, and appears to be dropping perpendicular to the horizon, as depicted in figure 6.2.5. How fast is the shadow of a 25 meter wall lengthening at the moment when the shadow is 50 meters long?
*Thursday, April 9, 2015 by John*

**calculus**

karen hits a tennis ball with an initial velocity of 42 feet per second an at angle of 16 degree with the horizontal from a height of 2 feet. she is 20 feet from the net and the net is 3 feet. will the ball go over the net?
*Wednesday, April 8, 2015 by BK*

**calculus**

consider the function f that is continuous on the interval [-5,5] and for which the definite integral 0(bottom of integral sign) to 5(top of integral sign) of f(x)dx=4. Use the properties of the definite integral to evaluate each integral: (a) definite integral from 0(on the ...
*Wednesday, April 8, 2015 by Linda*

**calculus**

A conical drinking cup is made from a circular piece of paper of radius R inches by cutting out a sector and joining the edges CA and CB. Find the radius, height and volume of the cone of greatest volume that can be made this way
*Wednesday, April 8, 2015 by Linda*

**Calculus**

A hot air balloon is 150 ft above the ground when a motorcycle passes beneath it (traveling in a striaght line on a horizontal road) going 58 ft/sec. If the balloon is rising vertically at a rate of 10 ft/sec, what is the rate of change of the distance between the motorcycle ...
*Wednesday, April 8, 2015 by Linda*

**calculus **

A conical drinking cup is made from a circular piece of paper of radius R inches by cutting out a sector and joining the edges CA and CB. Find the radius, height and volume of the cone of greatest volume that can be made this way.
*Wednesday, April 8, 2015 by Linda*

**Calculus (urgent help)**

consider the function f that is continuous on the interval [-5,5] and for which the definite integral 0(bottom of integral sign) to 5(top of integral sign) of f(x)dx=4. Use the properties of the definite integral to evaluate each integral: (a) definite integral from 0(on the ...
*Wednesday, April 8, 2015 by Linda*

**calculus**

A box with a square base is to be constructed with a surface area of 726 square centimeters. 1. Draw a diagram of the box. Label the diagram appropriately with variables. 2. Write an objective equation and a constraint equation (label each one as objective or constraint). 3. ...
*Wednesday, April 8, 2015 by Courtney*

**PRE - CALCULUS**

Solve the quadratic equation by the square root property. (2x + 5)2 = 49 A. {-6, 1} B. {0, 1} C. {-27, 27} D. {1, 6} d?
*Wednesday, April 8, 2015 by Ciara*

**PRE - CALCULUS**

Evaluate the radical expressions or indicate that the root is not a real number. 3sqrt-4^3 A. -64 B. 4 C. -4 D. not a real number B?
*Wednesday, April 8, 2015 by Ciara*

**Calculus**

When production is 1700, marginal revenue is 8 dollars per unit and marginal cost is 6.75 dollars per unit. Do you expect maximum profit to occur at a production level above or below 1700? If production is increased by 50 units, what would you estimate the change in profit ...
*Tuesday, April 7, 2015 by Nope*

**Calculus**

A wire 7 meters long is cut into two pieces. One piece is bent into a square for a frame for a stained glass ornament, while the other piece is bent into a circle for a TV antenna. To reduce storage space, where should the wire be cut to minimize the total area of both ...
*Tuesday, April 7, 2015 by Nope*

**calculus**

Solve the equation. Give the exact solution. 2*10^(5x-3)+5=17
*Tuesday, April 7, 2015 by Michael J*

**calculus**

Find the area under one arch of curve y=cos(x/4). This lesson is plane areas in rectangular coordinates. I don't know how to solve it. Thanks for your help.
*Tuesday, April 7, 2015 by Jhun*

**Calculus**

Evaluate dy/dt for 2xy-2x+2y^3=-10 with the conditions dx/dt=-4 x=2 y=-1 dy/dt=?
*Monday, April 6, 2015 by Frankzilla*

**Calculus**

Cost: C^2=x^2+98*sq rt of x + 57 Revenue:890(x-4)^2+29R^2=26,100 Find the marginal cost dC/dx at x=4
*Monday, April 6, 2015 by Frankzilla*

**Calculus**

Find the rate of change of total revenue, cost, and profit with respect to time. Assume that R9x) and C9x) are in dollars. R(x)=60x-0.5x^2 C(x)=5x+15 x=30 and dx/dt=20 units per day
*Monday, April 6, 2015 by Billy the Goat*

**Calculus**

a 14 foot ladder is leaning against a building. If the bottom of the ladder is sliding along the pavement directly away from the building at 3 feet/second, how fast is the top of the ladder moving down when the foor of the ladder is 5 feet from the wall? I got -1.083 when I ...
*Monday, April 6, 2015 by Billy the Goat*

**Calculus**

a 12 foot ladder is leaning against a building. If the bottom of the ladder is sliding along the pavement directly away from the building at 1 feet/second, how fast is the top of the ladder moving down when the foor of the ladder is 2 feet from the wall?
*Monday, April 6, 2015 by Billy the Goat*

**Pre-Calculus**

Convert from standard to vertex form: (x+5)(x+4) x^2+ 9x + 20 (x+3)^2 + 20 - 9 (x+3)^2 + 11 <------
*Monday, April 6, 2015 by Lucina*

**Calculus **

Let f(x)=(lnx)^4 f'(x)=4(ln(x))^3/x what is f'(e^2)=?
*Monday, April 6, 2015 by Dani*

**Calculus 2 (Series)**

Can anyone help me start this problem from beginning to end, along with explanations on how to go about the problem for a better understanding how to do this series problem? 1) Find the values of p for which the series is convergent. Summation notation symbol (with n=1 on ...
*Monday, April 6, 2015 by Sena*

**calculus**

A ball is thrown vertically upward with an initial velocity of 128 feet per second, the ball’s height after t second is s(t) = 128t – 16t². Find the instantaneous velocity at 4 seconds.
*Monday, April 6, 2015 by syu*

**calculus**

A ball is thrown from an initial height of 130 feet with an initial upward velocity of 35ft/s . The ball's height H (in feet) after T seconds is given by the following h=130-6t-16t^2
*Monday, April 6, 2015 by juan*

**Calculus**

1. integral (x^3 * sqrt(x^2-4)) dx I'm confused on how to start this problem, if I am doing trig substitution.
*Sunday, April 5, 2015 by K*

**pre calculus**

the downhill ski club is organizing a ski trip. group tickets for the ski trip are priced at 20 for the first 100 skiers and a discount of 5.00 for each of the skiers over 100. a) write a formula to find the average cost of x skiers. b)write a formula to find the average cost ...
*Friday, April 3, 2015 by syed*

**pre calculus**

the downhill ski club is organizing a ski trip. group tickets for the ski trip are priced at 20 for the first 100 skiers and a discount of 5.00 for each of the skiers over 100. a) write a formula to find the average cost of x skiers. b)write a formula to find the average cost ...
*Friday, April 3, 2015 by syed*

**Calculus**

List x1, x2, x3, x4 where xi is the right endpoint of the four equal intervals used to estimate the area under the curve of f(x) between x = 3 and x = 5. 3, 3.5, 4, 4.5 3, 3.2, 4.6, 5 3.5, 4, 4.5, 5 3.25, 3.75, 4.25, 4.75 my answer was a because i kept getting numbers like 3, ...
*Friday, April 3, 2015 by bob*

**calculus**

A rectangular area is to be enclosed and divided into thirds. The family has $400 to spend for the fencing material. The outside fence costs $10 per running foot installed, and the dividers cost $20 per running foot installed. What are the dimensions that will maximize the ...
*Friday, April 3, 2015 by Anonymous*

**Math/Calculus**

Solve the differential equation y'=3t^2+4. Solve the initial value problem y(0)=3. Separation of variables! My work: dy/dt= 3t^2+4 dy= 3t^2+4 dt Then you integrate both sides. ∫ dy= ∫ 3t^2+4dt Question: is there a 1 in dy? ( ∫ 1dy)? If so: y+C1=t^3+4t+C2 ...
*Thursday, April 2, 2015 by Sarah*

**calculus**

A closed cylindrical can is to hold 2 litter (200 cm³) of liquid. How should we choose the height and radius to minimize the amount of material needed to manufacture the can?
*Thursday, April 2, 2015 by nani*

**Calculus**

Use implicit differentiation to differentiate y=x^(8/37), by writing it as y^37=x^8. Express your answer only in terms of x.
*Thursday, April 2, 2015 by Anonymous*

**Calculus**

If two resistors with resistances R1 and R2 are connected in parallel, as in the figure, then the total resistance R, measured in Ohms (Ω), is given by: 1/R=1/R1+1/R2 If R1 and R2 are increasing at rates of .3Ω/s and .2Ω/s, respectively, how fast is R increasing...
*Wednesday, April 1, 2015 by Jen*

**Calculus**

1 pt) For positive constants k and g, the velocity, v, of a particle of mass m at time t is given by v=mg/k(1−e−kt/m). At what rate is the velocity is changing at time 0? At t=8? What do your answers tell you about the motion? At what rate is the velocity changing ...
*Wednesday, April 1, 2015 by Jen*

**calculus**

(1 pt) When air expands adiabatically (without gaining or losing heat), its pressure P and volume V are related by the equation PV1.4=C where C is a constant. Suppose that at a certain instant the volume is 390 cm3, and the pressure is 75 kPa (kPa = kiloPascals) and is ...
*Wednesday, April 1, 2015 by emily*

**calculus**

1 pt) Coroners estimate time of death using the rule of thumb that a body cools about 2 degrees F during the first hour after death and about 1 degree F for each additional hour. Assuming an air temperature of 68 degrees F and a living body temperature of 98.6 degrees F, the ...
*Wednesday, April 1, 2015 by emily*

**calculus**

Oil spilled from a ruptured tanker spreads in a circle whose area increases at a constant rate of 7.5 mi2/hr. How rapidly is radius of the spill increasing when the area is 10 mi^2?
*Wednesday, April 1, 2015 by Anonymous*

**Calculus **

Use implicit differentiation to differentiate y=x8/37, by writing it as y37=x8. Express your answer only in terms of x.
*Wednesday, April 1, 2015 by Anonymous*

**calculus**

A painting is hung on a wall in such a way that its upper and lower edges are 10 ft and 7ft above the floor, respectively. An observer whose eyes are 5 ft above the floor stands x feet from the wall. How far away should the observer stand to maximize the angle subtended by the...
*Wednesday, April 1, 2015 by Linda*

**calculus**

The operating cost, C, in dollars per hour, for an airplane cruising at a height of h metres and an air speed of 200km/h is given by: C = 4000 + h/15 + 15000000/h for the domain 1000 ≤ h ≤ 20000. Determine the height at which the operating cost is at a minimum, and...
*Tuesday, March 31, 2015 by sierra*

**Calculus 1**

How do you find the derivative of 1/3(x^2+2)^3/2 ? Please help
*Tuesday, March 31, 2015 by Danny*

**calculus**

cos2x=secx find x
*Tuesday, March 31, 2015 by Cody*

**Calculus **

A certain magical substance that is used to make solid magical spheres costs $800 per cubic foot. The power of a magical sphere depends on its surface area, and a magical sphere can be sold for $20 per square foot of surface area. If you are manufacturing such a sphere, what ...
*Monday, March 30, 2015 by Anonymous*

**Calculus study**

A baseball team plays in a stadium that holds 52000 spectators. With the ticket price at $9 the average attendance has been 21000. When the price dropped to $6, the average attendance rose to 26000. a) Find the demand function p(x), where x is the number of the spectators. (...
*Monday, March 30, 2015 by Juan *

**Calculus**

A small resort is situated on an island that lies exactly 5 miles from P, the nearest point to the island along a perfectly straight shoreline. 10 miles down the shoreline from P is the closest source of fresh water. If it costs 1.5 times as much money to lay pipe in the ...
*Monday, March 30, 2015 by Emily*

**calculus**

Find the point on the line 2x+4y+7=0 which is closest to the point (4,−3).
*Monday, March 30, 2015 by Emily*

**calculus**

A Norman window has the shape of a semicircle atop a rectangle so that the diameter of the semicircle is equal to the width of the rectangle. What is the area of the largest possible Norman window with a perimeter of 31 feet
*Monday, March 30, 2015 by Emily*

**Calculus **

The price-demand and cost functions for the production of microwaves are given as p=235−x40 and C(x)=14000+70x, where x is the number of microwaves that can be sold at a price of p dollars per unit and C(x) is the total cost (in dollars) of producing x units. (A) Find ...
*Monday, March 30, 2015 by Anonymous*

**Calculus **

A company decides to begin making and selling computers. The price function is given as follows: p=−70x+4000, where x is the number of computers that can be sold at a price of p dollars per unit. Additionally, the financial department has determined that the weekly fixed...
*Monday, March 30, 2015 by Anonymous*

**Calculus **

The total cost (in dollars) of producing x golf clubs per day is given by the formula C(x)=500+100x−0.1x2. (A) Find the marginal cost at a production level of x golf clubs. C′(x) = (B) Find the marginal cost of producing 35 golf clubs. Marginal cost for 35 clubs =
*Monday, March 30, 2015 by Anonymous*

**Calculus**

how can you find the bounderies given by the curve x=4sqrt(y) and y=4sqrt(x)? show your solution please. thanks to anyone who will notice this!
*Monday, March 30, 2015 by Lucy*

**Calculus**

Solve without a calculator. cos(arcsin (3x/2)) I made a triangle but im stuck after that..
*Sunday, March 29, 2015 by Anonymous*

**Calculus**

The integral of [(x+3)/(x^2+9)] dx I think you split it into two fractions but im not exactly sure what to do.
*Sunday, March 29, 2015 by Anonymous*

**calculus**

When air expands adiabatically (without gaining or losing heat), its pressure P and volume V are related by the equation PV1.4=C where C is a constant. Suppose that at a certain instant the volume is 330 cubic centimeters and the pressure is 99 kPa and is decreasing at a rate ...
*Sunday, March 29, 2015 by Anonymous*

**Calculus**

Integral of [1/(sqrt(8+2x-x^2))] dx
*Sunday, March 29, 2015 by Anonymous*

** Calculus**

Does the series (cos(k/3))^2/2^(k/3)+1 from k=1 to infinity converge?
*Sunday, March 29, 2015 by Jenn*

**Calculus**

Th integral of tan(3x)dx
*Sunday, March 29, 2015 by Anonymous*

**Calculus 1**

If two resistors with resistances R1 and R2 are connected in parallel, as in the figure below, then the total resistance R, measured in ohms (Ω), is given by 1/R= 1/R1+ 1/R2. If R1 and R2 are increasing at rates of 0.3 Ω/s and 0.2 Ω/s, respectively, how fast is ...
*Sunday, March 29, 2015 by TayB*

**Calculus**

Simplify using basic simplification. y=x^(1-x)
*Sunday, March 29, 2015 by Anonymous*

**Calculus**

Simplify using basic simplification. f(x)=ln[(sqrt(x^2+1))/(x(2x^3-1)^2)]
*Sunday, March 29, 2015 by Anonymous*

**Calculus**

Find the equation of the tangent line when x=2 for the functin f(x)=5^(x/2)
*Sunday, March 29, 2015 by Anonymous*

**Calculus 2 (Series - Convergent or Divergent?)**

Can someone show me a step by step process and explanation how to solve this problem? 1) Consider the following series. (∞ on top of summation symbol) (k = 1 under the summation symbol) ∑ k(k+15)/(k+13)^2 Determine whether the series is convergent or divergent. If ...
*Sunday, March 29, 2015 by Erin*

**Calculus 2**

I need help in solving an initial-value problem and a few series problems (Especially on #45 & #46). I don't really understand how to do the series problems...majority of the time. An explanation would be great as well. Thank you for your time. #20) Solve the initial-value...
*Sunday, March 29, 2015 by Erin*

**Calculus 2 - Series**

I am so confused on how to do series problems...especially these. How can you tell the pattern and determining the formula for them? Can someone please help? 26) Write the first five terms of the sequence {an} whose nth term is given. an = (n + 3)/(2n − 1) a1 = ? a2 = ? ...
*Sunday, March 29, 2015 by Helen*

**Calculus 2 (Differentiate & Decay Problem)**

I have two problems I need help on, can someone show and explain step by step how to do the problems? For #1, how would you differentiate and solve the inital-value problem? For #2, I don't understand what I am doing wrong with the problem..I am sure it is a decay problem...
*Sunday, March 29, 2015 by Misa*

**Calculus**

The area of a circular oil slick is increasing at a constant rate of 2 square miles per day. How fast is the radius increasing when the area is 4(pi) square miles (approximately 12.57 square miles)? So far I have that the area increases at the rate of x+(2mi^2/d) but I don'...
*Sunday, March 29, 2015 by Emily *

**Differential Calculus**

Hi pls help me i dunno what to do show me complete solution please please Thank you. a piece of wire 10ft. long is cut into two pieces , one piece is bent into the shape of a circle and the other into the shape of a square. How should the wire be cut so that: a.)The combined ...
*Sunday, March 29, 2015 by Ella*

**integral calculus **

(x^4+6x^3-x^2+2)dx need help
*Sunday, March 29, 2015 by Olya*

**integral Calculus **

ʃ (x4 + 6x3 – x2 + 2)dx I really need it for practicing this subject...please please help
*Sunday, March 29, 2015 by Olya*

**Calculus **

1. Prove that, among all rectangles with fixed perimeter p, where p > 0, the largest in area is a square. 2. A 2 × 3 array of six congruent rectangular pigpens (that all look the same from above) will be in the overall shape of a rectangle R. We may use 100 feet of ...
*Friday, March 27, 2015 by Andy*

**Pre-Calculus**

Solve 0 = 3x^2 + 5x -1 by completing the square. Express your answer as exact roots. 3(x^2 + 5/3 + 25/36) = -1 (x+ 5/6)^2 = 37/36 sq root( x + 5/6)^2 = sq root (37/36) x + 5/6 = +- sq root 37/6 x = -5/6 +- square root 37 /6 <--- (Sorry for the work being so messy! It'd ...
*Thursday, March 26, 2015 by Lucina*

**calculus**

A particle moves on a line so that its position at time t seconds is p(t)=3t3 meters to the right of the origin. Find the time c in the interval (4,8) for which the velocity of the particle at time c is equal to the average velocity on the interval [4,8].
*Thursday, March 26, 2015 by Ella*

**Calculus 2 (Differential Equation)**

How would you solve the following problem explicitly? Sqrt(1-y^2) dx - sqrt(1-x^2) dy I separated the x and y terms and got: Integral of 1/sqrt(1-x^2) dx = Integral of 1/sqrt(1-y^2) dy I was wondering how would you take the anti-derivative of each function. I believe we are ...
*Thursday, March 26, 2015 by Rena*

**Calculus **

Find the elasticity of the demand function: pq = 42 p=$2 My professor went through this lesson really fast and I would appreciate anyone's help in explaining it. Thank You
*Wednesday, March 25, 2015 by Tom*

**Calculus **

A manufacture has been selling 1300 television sets a week at $420 each. A market survey indicates that for each $16 rebate offered to a buyer, the number of sets sold will increase by 160 per week. a) Find the price p(x) of each television as a function of x, where x is the ...
*Wednesday, March 25, 2015 by Danielle*

**Calculus**

A model for the food-price index (the price of a representative "basket" of foods) between 1984 and 1994 is given by the function I(t)=0.00009045t5+0.001438t4−0.06561t3+0.4598t2−.6270t+99.33 Where t is measured in years since midyear 1984, so 0&#...
*Wednesday, March 25, 2015 by Danielle*

**Calculus**

The manager of a large apartment complex knows from experience that 80 units will be occupied if the rent is 460 dollars per month. A market survey suggests that, on the average, one additional unit will remain vacant for each 10 dollar increase in rent. Similarly, one ...
*Wednesday, March 25, 2015 by Danielle*

**calculus**

Find the intervals on the x-axis on which the function f(x) is increasing and those which it is decreasing, where f(x) = (x)/(x^2+1) I differentiated and got f'(x)=(x^2+1) -(x)(2x) all over (x^2+1)^2 But I don't know what to do now...
*Wednesday, March 25, 2015 by paula*

**Elasticity Demand Calculus **

Find the elasticity of the demand function: pq = 42 p=$2 My professor went through this lesson really fast and I would appreciate anyone's help in explaining it. Thank You
*Wednesday, March 25, 2015 by Tom*

**Pre-Calculus**

Solve. Express your answer as exact roots. (s+6)^2 = 3/4 Sq root (s+6)^2 = +-sq root 3/4 (s+6) = sq root 3/ 2 s = -6 +- sq root 3 ----------------- 2 (The answer according to the textbook is (-12 +- sq root 3)/2. What error have I made?) Thank you
*Wednesday, March 25, 2015 by Lucina*

**Calculus**

Santr 109 (a fictitious substance) decays by about 6% every day. How much of a 84 pound sample remains after: (a) 7 days (b) 3 weeks (b) 48 days
*Tuesday, March 24, 2015 by Irina*

**calculus**

A cattle rancher wants to enclose a rectangular area and then divide it into six pens with fencing parallel to one side of the rectangle (see the figure below). There are 540 feet of fencing available to complete the job. What is the largest possible total area of the six pens?
*Monday, March 23, 2015 by Connor*

**Calculus**

Let f(x)=5x2+5x−12. Answer the following questions.Find the average slope of the function f on the interval [−1,1].Verify the Mean Value Theorem by finding a number c in (−1,1) such that f′(c)=m¯¯¯.
*Monday, March 23, 2015 by Aggie123*

**Calculus**

The circumference of a sphere was measured to be 76.000 cm with a possible error of 0.50000 cm. Use linear approximation to estimate the maximum error in the calculated surface area.Estimate the relative error in the calculated surface area.
*Monday, March 23, 2015 by Aggie123*

**Calculus**

A street light is at the top of a 15 ft tall pole. A woman 6 ft tall walks away from the pole with a speed of 5 ft/sec along a straight path. How fast is the tip of her shadow moving when she is 50 ft from the base of the pole?
*Monday, March 23, 2015 by Aggie123*