Math 31AL Worksheet
Tuesday, N ov 5 (Week 6)
Guidelines for these problems:
1. Identify variables. Note which ones are functions of time (i.e. actual variables, varying
with time, as opposed to just constants). It may help to draw a picture.
2. What is given in the problem? (Try to restate in terms of the variables, from step 1.)
3. What do you need to find? (Try to restate in terms of the variables.)
4. Come up with an equation that relates the variables to each other.
5. Solve: Differentiate both sides of the equation with respect to t, applying the chain
rule, product rule, etc, wherever necessary. Plug in any values given in the problem.
Notes:
•One (or more) of the givens in the problem will be a rate of change of some variable.
•The thing you are supposed to find will usually also be a rate of change, of a different
variable.
•Remember, if you’re given a specific value of one of the variables that’s changing with
time,don’t plug that value in until after taking the derivative in step 5.
