1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Calc Word Problem

  1. Oct 26, 2011 #1
    1. The problem statement, all variables and given/known data
    A farmer can sell his crop for p= -t^2+60t+100 dollars per ton, where p is price and t is the number of days after Oct. 1st. Additionally, the farmer must sell his crop on or before Oct. 10 to pay his outstanding credit card bills. On what day should he sell to maximize profit?

    2. Relevant equations

    3. The attempt at a solution
    Last edited by a moderator: Oct 26, 2011
  2. jcsd
  3. Oct 26, 2011 #2
    What have you attempted so far, and where are you stuck?
  4. Oct 26, 2011 #3
    I get -2t + 60 = 0
    -2t = -60
    Multiple choice answers give 8 options from Oct. 4th through Oct. 11?
  5. Oct 26, 2011 #4


    User Avatar

    Staff: Mentor

    How does the additional constraint stated in the problem change your answer?
  6. Oct 26, 2011 #5


    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper

    Selling price is not necessarily equal to profit. Have you provided all parts of the problem you were asked to solve?
  7. Oct 26, 2011 #6
    I'm confident t=30 is correct, but is the day to sell to max profit Oct. 31? As t = # of days after Oct. 1. Oct. 31 is not one of the multiple choice options?
  8. Oct 26, 2011 #7
  9. Oct 26, 2011 #8
    When looking for a max (or min) of a function, you also look at the endpoints of the interval over which the function is defined, in this case, at t = 0 and t = 9 (not t = 10 since Oct 1 is day 0)
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook