Optimization Problem Guide:

The Steps
Your Problem
  1. Understand the problem.
    1. Draw a picture.
    2. Which quantities are given?
    3. What is unknown?

  2. Choose the variables.
    1. Decide which quantity is to be maximized or minimized. Call it Q or some name that relates to the problem.
    2. Choose other variables for unknown quantities and label your diagram.

  3. Express Q as a function of one unknown.
    1. Express Q in terms of the variables in step 2. (This is your objective function.)
    2. Use other information in the problem to solve for all variables in terms of one variable (say x).  (You are using the constraint equation here.)
    3. Substitute for the other variables in the formula for Q (from the preceeding step) so that x is the only variable in the formula. Express the formula obtained in function notation: Q(x) = __

  4. Find the domain for the function Q(x).

  5. Use calculus to find the global maximum or minimum value of Q(x) over the domain.
    1. Compute Q'(x) and find all critical values of Q on the domain. (Note: Critical values are all stationary points in the domain, all points where the derivative does not exist and endpoints if the domain is a closed interval.)
    2. Evaluate Q(x) at each of the points found in the step above.
    3. Compare the values to determine the maximum or minimum value. Then determine which x gives you that Q value.

  6. Convert the results obtained in step 5 back into the context of the problem. Be sure you answer the question that was asked.


Disclaimer