Sunday

April 26, 2015

April 26, 2015

Number of results: 20,886

**Operations research**

36) Consider the following minimization problem: Min z = x1 + 2x2 s.t. x1 + x2 ≥ 300 2x1 + x2 ≥ 400 2x1 + 5x2 ≤ 750 x1, x2 ≥ 0 What is the optimal solution?
*December 12, 2010 by Pauline*

**Calc**

Can someone help me with this calc problem? lim as x->0 (tan^3 (2x))/(x^3)
*January 8, 2009 by Nick*

**MINIMIZATION PROBLEM (CALC)**

A wire 9 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 figures...
*October 30, 2010 by Pierre*

**MINIMIZATION PROBLEM (CALC)**

A wire 9 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 figures...
*October 30, 2010 by Pierre*

**Maths**

There is a point (P) on the graph of [x^2+y^2- 136 x + 12 y + 4560 = 0] and a point(Q) on the graph of [(y + 6)^2 = x^3 - 116 x^2 - 417 x + 267460] such that the distance between them is as small as possible. To solve this problem, we let ((x,y) be the coordinates of the point...
*November 19, 2009 by Salman*

**Math**

There is a point (P) on the graph of [x^2+y^2- 136 x + 12 y + 4560 = 0] and a point(Q) on the graph of [(y + 6)^2 = x^3 - 116 x^2 - 417 x + 267460] such that the distance between them is as small as possible. To solve this problem, we let ((x,y) be the coordinates of the point...
*November 19, 2009 by Salman*

**Calculus**

There is a point (P) on the graph of [x^2+y^2- 136 x + 12 y + 4560 = 0] and a point(Q) on the graph of [(y + 6)^2 = x^3 - 116 x^2 - 417 x + 267460] such that the distance between them is as small as possible. To solve this problem, we let ((x,y) be the coordinates of the point...
*November 19, 2009 by Salman*

**Maths**

There is a point (P) on the graph of [x^2+y^2- 136 x + 12 y + 4560 = 0] and a point(Q) on the graph of [(y + 6)^2 = x^3 - 116 x^2 - 417 x + 267460] such that the distance between them is as small as possible. To solve this problem, we let ((x,y) be the coordinates of the point...
*November 20, 2009 by Salman*

**Math**

There is a point (P) on the graph of [x^2+y^2- 136 x + 12 y + 4560 = 0] and a point(Q) on the graph of [(y + 6)^2 = x^3 - 116 x^2 - 417 x + 267460] such that the distance between them is as small as possible. To solve this problem, we let ((x,y) be the coordinates of the point...
*November 20, 2009 by Salman*

**Calculus**

There is a point (P) on the graph of [x^2+y^2- 136 x + 12 y + 4560 = 0] and a point(Q) on the graph of [(y + 6)^2 = x^3 - 116 x^2 - 417 x + 267460] such that the distance between them is as small as possible. To solve this problem, we let ((x,y) be the coordinates of the point...
*November 20, 2009 by Salman*

**Science**

What are waste minimization components?
*November 5, 2007 by J*

**Calc or Pre calc**

I am having trouble doing this problem. I know how to do indefinate integrals, but I don't know how to do definate integrals. Can you show me how to do this. Evaluate 5 (x^3-2x)dx 2
*May 14, 2008 by jennifer*

**Math**

If (a,-3) is a point on the graph of y=x^2+4x, what is the value of a? so far i have -3=x^2+4x i can do the problem on my graphing calc but we can't use a graphing calc on the test so i need to know how to do it by hand. what do i do next?
*January 20, 2010 by Karen*

**Pre-Calc**

I'm stuck on a pre-calc problem. I need to find y as a function of x, where the constant c is a positive number for In(y-1)+In(y+1)= -x+c express your question as ln[(y-1)(y+1)] = -x+c change that to exponential form e^(-x+c) = (y-1)(y+1) e^(-x+c) = y^2 - 1 y^2 = e^(-x+c) + 1 ...
*May 9, 2007 by Sarah*

**Science**

How is waste minimization bad locally in USA?
*November 5, 2007 by J*

**Science**

Topic: Waste Minimization How bad is it locally (USA)?
*November 6, 2007 by J*

**Micro economics**

Consider a firm with the following production function: q = (ak+bl)^(1/2) The firm's total costs can be written as C = F + rk + wl 1. Calculate the firm's contingent factor demand. Illustrate it in a graph including the firm's isoquant map 2. Assume that r/w > a/b. Find the...
*April 8, 2014 by Rasmus*

**math**

Hi, How do I improve my math skills? I can't calculate in my head (I.e 2x43), I would actually have to write it down to solve it. I took pre-calc, calc and didnt have problem understanding. I don't know what is wrong. what should I do?
*February 27, 2015 by john*

**AP Calc**

When a chain hangs under its own weight, its shape is catenary. The equation of a catenary with a vertex on the y-axis is y=e^x+e^-x. Find the length of the chain from x=-2 to x=2. Then use the same technique from Problem #8(Previous AP calc problem I posted) to find the ...
*July 31, 2014 by Anon*

**Calc**

A student is in a 20 week calc class. The function f(t)=50-50e^0.2t f(t) measures the students problem speed in t weeks -how many problems per hour can a student solve at the beginning of the course - how many problems per hour can a student solve halfway through the course -...
*July 20, 2012 by Marshall*

**calc**

y=ln(x+1) +ln(x-1) find dy/dx I have trouble with this problem since i'm not that familar with finding the derivative when they involve ln. Please show me how to solve this problem. I should have gotten 2x/(x^2-1)
*January 17, 2007 by Brian*

**College microeconomics**

Need some help with these questions....Thanks in advanced. All profit-maximizing firms hire inputs up to the point where: A) MRP = W B) MR = MC C) MP = W D) MFC = MRP E) MFR = MRC 4) A firm’s marginal revenue product of labor curve A) is steeper than its demand curve for labor...
*April 14, 2009 by sue*

**finite math**

when doing minimization problems and there is more than one negative constant in the far right column is there a method for choosing the proper one to go with or is the process entirely arbitraru
*March 4, 2007 by chris*

**C code**

Write a .c file named calc that: - Takes arguments from the command line - Solves a simple math problem - Returns the result as an exit status calc.c: //this is the function that gets called when the executable is run. int main(int argc, char * argv[]){ //I've given you the ...
*February 6, 2013 by Nick*

**pre calc**

what are some point for the problem y=1/2x+2
*September 15, 2009 by jasmine*

**Calc**

This is a very confusing problem for me y = 5^3^x^2 Find y'
*October 21, 2009 by Joe*

**Calc**

I need help solving this problem. logbase5(x+2)=2
*July 12, 2011 by Leanna*

**Calc**

y=ln(x+1) +ln(x-1) find dy/dx I have trouble with this problem since i'm not that familar with finding the derivative when they involve ln. Please show me how to solve this problem. I should have gotten 2x/(x^2-1) The derivative of ln(x) is 1/x So, you obtain dy/dx = 1/(x+1...
*January 18, 2007 by Brian*

**pre calc**

how do i tackle this problem?!? cosx=sinx*cotx
*February 9, 2010 by jill*

**Calc.**

Solve the initial value problem explicity: y'= 5xe^(-y), y(1)=1
*February 2, 2011 by Tania*

**Calc pt2**

Original question: Posted by Lost One on Tuesday, March 5, 2013 at 12:04pm. Let f(x) = (2/3)x^3 - 2x + 1 with a restricted domain of [1,infinity]. What is the value of (f-1)'(x) when x = 13? •Calc - Steve, Tuesday, March 5, 2013 at 12:58pm since x = f^-1(y) and dx/dy = 1/y' f...
*March 5, 2013 by Lost One*

**pre-calc help !!!!!!!**

if someone could show me how to solve this problem 1) cos(345°)
*November 28, 2012 by Haley*

**Calc**

Find the integral from -∞ to -1 of 1/(1+x²) dx. I started working the problem out, and so far I got the lim as z→-∞ of [arctan (-1) - arctan (z)]. I'm a little bit confused exactly what is means when you plug -∞ into z, and how to solve the problem from...
*October 24, 2011 by Erica*

**Pre Calc**

Can someone help me understand how to do this: I need to find two solutions to the problem (x-2)^2 + (y+3)^2 = 9
*March 15, 2009 by Anonymous*

**Pre-Calc**

Please help me with this problem-I'm stuck (x-2)/(x+2) = (x+10)/x I'm not even sure where to start-Thanks for any help you can provide
*September 18, 2011 by Josh*

**Calc 1**

I need help solving for this final problem to complete my assigment. Please help! Solve for x: ln(x^4)-ln(x^2)=2
*September 24, 2012 by arcos15*

**Chemistry**

A .682 g sample of an unknown weak monoprotic acid, HA, was dissolved in sufficient water to make 50mL of solution and was titrated with a .135 M NaOH solution. After the addition of 10.6mL of base, a pH of 5.65 was recorded. The equivalence point was reached after the ...
*May 9, 2007 by Sara*

**Calc 121**

Okay, how would you go about finding the area of a curve from 1 to 4, when y=2x+(2/(x^2))?? It's not like the problem I asked before because here, you cannot use substitution. I tried using 2x for u and x^2 for du but it won't simplify into a ln problem or anything that I can ...
*April 21, 2007 by Me*

**Studying for Calc**

I have a quiz on derivatives coming up and I really want to do well, but i'm not sure how to go about studying calc. i have no trouble studying for other subjects, but i'm doing poorly in calc and i need to make some changes in my study habits. any suggestions? i usually work ...
*October 7, 2008 by Elizabeth*

**calc**

cylindrical shells the problem says rotate about the x-axis these are the two equations given: x+y=3 AND x-4=-(y-1)^2
*February 1, 2010 by robert*

**math/Calc**

g(x)={1+cos(pi/2-x/1) 0 for-2 <or= x <or=2 for x<2 or x>2 is g(x) continuous at x=2 is it differentiable at x=2? ex[lain in detail I'm very confused as to how to solve this problem
*February 9, 2012 by angie*

**MATHS**

A CONE WAS CONSTRACTED FROM PLASTIC, HAVE A HEIGHT OF 20cm (PART C). THE LID IS MADE UP OF HEMISPHERE HAVE RADIUS 0F 5cm (PART A) AND PYRAMID HAVE VOLUME OF 81,667cm³. THE LID FITS EXACTLY OVER THE CONE. A) CALC. THE VOL. OF PART A. B) CALC. THE VOL. OF PART C. C) CALC. THE ...
*August 9, 2010 by MTHOMBENI BAFANA*

**calc**

If 4x2+3x+xy=2 and y(2)=–10 , find y'(2) by implicit differentiation. i keep getting the wrong answer for this problem evn when plugging 2 in for y.
*May 8, 2008 by sara*

**calc**

If 4x2+3x+xy=2 and y(2)=–10 , find y'(2) by implicit differentiation. i keep getting the wrong answer for this problem evn when plugging 2 in for y.
*May 9, 2008 by sara*

**Pre-Calc**

I am stuck solving this problem, any help please..Many thanks find all numbers x that satisfy the given equation ln(2x) ------- =2 ln(3x)
*December 9, 2010 by Roy*

**Pre-Calc/Calc**

Which set of parametric equations corresponds to this rectangular equation? y=2x-(x^2 / 10) A. x=4t, y=4t-(t^2 /10) B. x=2t, y=8t-(4t^2/10) C. x=2t, y=4t-(4t^2/10) D. x=.5t, y=2t-(t^2/10) E. x=t, y=t-(t^2/10)
*April 17, 2013 by Chris Math Hw Help*

**calc**

Consider the function f(t)=2sec^2(t)–10t^3. Let F(t) be the antiderivative of f(t) with F(0)=0. Then F(2) my problem is i get 2tan(t)-5/2t^4+c i plug in 2 and dont get the right answer please help
*June 5, 2009 by sonia*

**calc**

f(x)=8cos4x What is the derivative? Im doing online homework and i keep getting an incorrect answer. How do you work out this problem correctly? thanks
*April 26, 2010 by Adam*

**Calc**

If y=3x^2-2, then dy/d(2x-3)= ? I've never taken derivatives with respect to anything other than a single variable, such as x, y or t, so i'm not sure how to start this problem! Thanks
*February 6, 2015 by Anon*

**help chem!:/**

a) Calc. PH of 0.010 M HF and 0.030 M KF e) calc. PH Zn(OH)2 in wAter
*March 15, 2012 by ALISON*

**ap calc**

find the volume generated by revolving the area bounded by y=-x^3, y=0, and x=-2 about the line x=1. I know how to the solve the problem but am not sure how to get the interval. Please help.
*February 28, 2015 by anonymous*

**Pre Calc**

Does this: sqrt 3x-4=(x-4)^2-3 Multiply out to: x^4-16x^3+90^2-211x+173 I then need to put it in the graphing calc and see what the roots are.
*September 10, 2009 by muffy*

**PLEEEEEEASE HELP, EMERGENCY!!!!!**

Here is a word problem dealing with The Simplex Method: Maximization, Minimization A dietitian is designing a daily diet that is to contain at least 60 units of protein, 40 units of carbs, and 120 units of fat. The diet is to consist of two types of foods. One serving of food ...
*October 25, 2006 by Dolores*

**calculus (limits)**

lim h>0 sqrt(1+h)-1/h not sure how to factor this; not allowed to use L'Hopital's Rule. (that isn't taught at my school until Calc II & I'm in Calc I).
*January 22, 2011 by John*

**Pre-Calc**

f(x)=(24x3+68x2+24x−32)/(4x3+56x2+236x+280) I need help finding the roots and the hole for this problem.
*September 30, 2012 by Richard*

**Science**

The topic is waste minimization. One of the questions that i need information on is this: How bad is it locally (USA)? In case locally in USA. Whats bad waste.
*November 6, 2007 by Plez Help!:"(*

**pre-calc**

Find a vector perpendicular to the plane containing the given points. (0,-2,2), (1,2,-3), and (4,0,-1) My teacher was unable to finish the lesson, but I'd like to know how to solve this problem.
*February 17, 2010 by James*

**Calc-Derivative**

Find the derivative of x^(1/x). Can someone show me steps for this problem...I go round in circles
*December 9, 2012 by Anon*

**Pre-Calc**

I am seeking help with this problem Please...Thank you! Find the point on the line y=x+3 in the xy-plane that is closest to the point (3, 2)
*December 7, 2010 by Roy*

**calc**

integrate (3+x)x^(1/2)dx=? please help I have no idea how to integrate this problem
*January 19, 2015 by Anonymous*

**Pre Calc**

use properties of the trigonometric function to find the exact value of each expression. Do no use a calculator. sec ( - pi/18) * cos (37 pi)/18 I do not see how to do this problem. Every time I do it out I get a reference angle of twenty degrees which isn't on the unit circle...
*November 13, 2009 by Pre Calc*

**Pre-Calc**

medication duration using the function of e through time lapse problem D(h)=8e(up carrot)-0.31(h) find med level at 1 hour- no problem 5.88mg. but every time I insert 4 for the 4 hours I get a larger number... much larger indicting the med level has gone up. I am sure it is my...
*February 21, 2010 by BecKi*

**math- pre calc/trig**

Find the length of each side of a square if the diagonal is 7(square root 2)? How do I solve or set up this problem?
*September 30, 2014 by jen*

**math, calc 2**

Using the disk method, find the volume of a right circular cone with height h and base radius r. I know the answer is 1/3pier^2h, but how do you explain or work out the problem?
*January 17, 2007 by George*

**Extrema-Calc**

Find and classify the relative maxima and minima of this function f(x)= definite integral sign where a=0 and b=x. t^2-4/(1+(cos^2(t)) dt what should my value for u be? is it just t. not sure how to even tackle this problem.
*May 15, 2013 by Eric*

**Pre-CALC**

Can anyone help me with this problem step by step please... Find the area inside the ellipse in the xy-plane determined by the given equation x^2 y^2 ____ + ___ =1 10 25
*December 7, 2010 by Amy*

**math**

One of the following functions is neither odd nor even. Which one? x^5 + 3x 6x^2 – |x^2| + 3 x^9 + 3x^7 + 6x (my answer)x^2 + 3x + 3 + |x –3| This is really tricky pre-calc graphing problem. Thanks for the help!
*October 1, 2012 by Anonymous*

**Calc**

Use a table of values to estimate the value of the limit. lim (tan 3x/tan 5x) x--> 0 I have no clue what to do. Could someone please explain how to go about this problem.
*September 26, 2010 by CMM*

**AP Calc**

Use mathematical induction to prove that the statement holds for all positive integers. Also, can you label the basis, hypothesis, and induction step in each problem. Thanks 1. 2+4+6+...+2n=n^2+n 2. 8+10+12+...+(2n+6)=n^2+7n
*August 5, 2012 by Brock*

**Calc 121**

Okay, how would you go about finding the area of a curve from 1 to 4, when y=2x+(2/(x^2))?? It's not like the problem I asked before because here, you cannot use substitution. I tried using 2x for u and x^2 for du but it won't simplify into a ln problem or anything that I can ...
*April 22, 2007 by Me*

**pre Calc.**

Describe the behavior of the function near the vertical asymptote. Is there another way to word this problem so that I might understand? Seriously, I have gotten everything so far, so is this just worded weird?
*November 1, 2010 by L.*

**AP Calc**

Find the volume of the solid generated by rotating the region bounded by the graph of y=x^2, y=0, x=1, and x=3 about the line parallel to the x-axis and one unit below it. Please help I have no idea how to solve this problem.
*March 1, 2015 by anonymous*

**Word Problem Cost minimization**

Don Garcia needs at least 24 units of vitamin A per day. Each green pill provides 4 units and each red pill provides one unit. Green pills cost 3.5Â¢ each and red pills cost 1Â¢ each. How many of each kind of pill should he take to minimize his cost? Green pills cost (3.5 ...
*July 22, 2005 by GetYourLeash*

**PRE-CALC**

Hi here is my question: Solve: (x-3)/x+3/x2=-6/x^2+2x For my solutions, I got -2 and 0, but the problem is, when I plug the numbers back in, I have zero in the denominator which I know you can't have. I'm not sure what I did wrong, or is it just undefined?
*October 16, 2009 by Muffy*

**Calc**

A 100 inch piece of wire is divided into 2 pieces and each piece is bent into a square. How should this be done in order of minimize the sum of the areas of the 2 squares? a) express the sum of the areas of the squares in terms of the lengths of x and y of the 2 pieces b) what...
*November 16, 2010 by katie*

**Calc B/C**

Assume no air friction and that the acceleration due to gravity is 10 meters/sec^2. A ball is moving horizontally at a rate of 5 meters/sec. until it falls off the edge of a platform. The height, h, of the platform would have to be ___ meters if the ball hit the ground 8 ...
*February 7, 2015 by Anon*

**calc**

I am not sure how to approach this...I have to find the value of x that makes the derivate of f(x) equal to zero...here's what I have so far (is it correct?) and how is the problem finished? Thank you very much! f(x) = (1/x) + ln(x) f'(X) = ln|x| + (1/x) 0 = ln|x| + (1/x) how ...
*October 2, 2010 by APpreciate student*

**calculus**

i'm having trouble with a problem in my calc class...it isn't really calculus yet since we're still in the review section but it goes somethign like this: ( don't have it in front of me) a rational function is defined by: R/(x-K) where R and K are constants. find R and K for a...
*March 15, 2007 by Rob*

**chemistry**

This problem is from my chemistry book and I am having a little trouble with the intermediary steps: Barium metal crystallizes in a body- centered cubic lattice (atoms at lattice points only) The unit cell edge length is 502 pm, and the density of the metal if 3.5g/cm^3. (...
*May 18, 2010 by Tokey*

**Calc Repost**

Express the function in the form f o g. G(x)= The cube root of (x/1+x) So, (f 0 g)(x)= f(g(x))= f(cube root of x/1+x)= I don't know how to finish the problem because it does not give you the information for F(x)???
*September 20, 2010 by Chelsea*

**Pre-Calc**

Can you show me how to find the rectangular equation of r=2costheta + 3 sin theta All I need is an example to work off I was absent today from Pre-Calc and I have homework to do and no explanation with them-Please help with this one Thank you
*October 3, 2011 by Leah*

**Calc Math**

A plane is heading on a bearing of 200° with an air speed of 400 km/h when it is blown off course by a wind of 100 km/h from the northeast. Determine the resultant ground velocity of the plane. What was your solution to answering this problem?
*February 22, 2015 by Amyy*

**My Friend Needs Help With a Calc Problem.**

how does five degrees east of north keep a plain going north when the wind pushes the plain four point six degrees west of north? This is not calculus. It is a vector problem. THe wind is pushing the plane west. If you need the solution, to find the direction of the wind, a ...
*October 12, 2006 by Sarah*

**Calc help**

find the area of the region enclosed by y=e^2x, y=e^5x, and x=1. i am having trouble seeing how this region looks like and having problems with how to start the problem in general. Much help is appreciated.
*February 19, 2009 by James*

**AP CALC**

Find the POSITIVE value of x that satisfies the mean value theorem for f(x)=sin(x) on the closed interval [-3pi/2, 3pi/2]. please help I have no idea how to solve this problem
*December 21, 2014 by Anonymous*

**Pre Calc!**

Two ships, one sailing at 30 km/hr and the other at 45 km/hr, left port at the same time. Three hours later they were 120 km apart. If you had to find the angle between their courses an equation that could be used to solve this problem is:
*May 24, 2010 by Ilene*

**Math**

A student is in a 20 week calc class. The function f(t)=50-50e^0.2t f(t) measures the students problem speed in t weeks -how many problems per hour can a student solve at the beginning of the course - how many problems per hour can a student solve halfway through the course -...
*July 20, 2012 by Marshall*

**Pre-Calc**

Can anyone help with the following problem please...Thank u so much Let f(x) =|9x|. For the area above the x-axis and between the lines x= -9 and x=18 a. draw and label a sketch with the area shaded b. find the area of the region in the xy-plane under the graph of f(x)
*December 8, 2010 by Amy*

**probability**

The vertical coordinate (“height") of an object in free fall is described by an equation of the form x(t)=θ0+θ1t+θ2t2, where θ0, θ1, and θ2 are some parameters and t stands for time. At certain times t1,…,tn, we make noisy observations Y1,…,Yn, ...
*April 2, 2014 by A*

**Pre-Calc**

A page that is x inches wide and y inches high contains 30 square inches of print. The top and bottom margins are 2 inches deep, and the margins on each side are 2 inches wide. a. draw a diagram that gives a visul representation of the problem. b. show that the total area A on...
*January 22, 2014 by Andy G*

**calc II**

Express the integrals as the sum of partial fractions and evaluate the integral: (integral of) (x^2)dx/(x-1)(x^2 +2x+1) My work: The above integral is equal to x^2dx/(x+1)^2 (A/x-1) + (B/x+1) + (Cx+D)/(x+1)^2 = x^2 A(x+1)^2 + B(x-1)(x+1) + (Cx+d)(x-1) = x^2 Ax^2 + 2Ax + A + Bx...
*December 6, 2009 by Jenna*

**confused calc**

dy/dx=2y^2 and if y=-1 when x=1, then when x=2, y=? (you already posted this, but i still don't get it) dy/dx = 2y^2 Integrating...y=2/3 y^3 + C put 1,-1 into the equation, and solve for C c=-1/3 so the equation is y=(2y^3)/3-1/3 then i have to find what y equals when x=2. how...
*December 12, 2006 by david*

**Pre-calc**

Can someone please show me the steps to this problem...Thanks in advance. Let f(x) = Ð9xÐ. For the area above the x-axis and between the lines x= -9 and x=18 a. draw and label a sketch with the area shaded b. find the area of the region in the xy-plane under the graph of f(x)
*December 7, 2010 by Amy*

**ISDS **

The optimal total shipping cost in a minimization transportation model is $622, and the reduced cost from source node 1 to destination node 6 is $6. This implies that if one were to deviate from the optimal solution by shipping one unit from node 1 to node 6, the new minimum ...
*March 13, 2012 by jamaal*

**Pre-Calc **

The concentration C of a chemical in the bloodstream t hours after injection into muscle tissue is C=3t^2+t/ t^3+50 A. Determine the horizontal asymptote of the function and interpret its meaning in the context of the problem. B. approximate the time when the bloodstream ...
*January 20, 2015 by Sam*

**Calc: Difference quotients**

"Use difference quotients with delta(x)=0.1 and delta(y)=0.1 to estimate fx(1,3) and fy(1,3) where f(x,y)=e^(-x)sin(y)." I don't know how to solve this problem. Could someone walk me through it? Thank you so much!
*February 27, 2011 by Brittany*

**chemistry**

liquid heptane C7H16 is completely combusted to produce CO2 and H2O: C7H16 + 11O2 --> 7CO2 + 8H2O the heat combustion for one mole of C7H16 is -4.85*10^-3 CO2 heat of comb. = -393.5 H2O h of c= -285.8 a) calc. the vale of heat of cumbustion for C7H16 in kJ/mol a .0108 mol ...
*March 10, 2010 by hilde*

**Calc Help**

Marginal Cost = 30sqroot(x+4) with fixed costs of $1000. Marginal Revenue = 900. find profit or loss from production and sale of 5 units. how many units will result in a max profit? what is the max profit? Can someone please help. Trying to review for my final and really stuck...
*April 29, 2007 by Rob*

**trig/pre -calc**

hello, i don't quite understand how to do this type of problem: 1. find the exact value of sin (pi/3). even more confusing is 2. find the exact value of csc^-1 (1). i would appreciate any kind of help! thank you!
*July 14, 2008 by brandy*

**Calc I**

I really need assistance!! I am to write an equation so that I can graph it. I do not understand how to graph OR write the equation for: x^2-y^2=16 for a tangent and normal line??? I keep coming up with the wrong answers...and the problem is I was not given any points of (x,y...
*June 28, 2011 by Kejo *