Section 3.6: Related Rates

Suggestions for Solving Related-Rates Problems

1. Sketch a figure if helpful.
2. Identify all relevant variables, including those whose rates are given and those whose rates are to be found.
3. Express all given rates and rates to be found as derivatives.
4. Find an equation connecting the variables identified in step 2.
5. Implicitly differentiate the equation found in step 4, using the chain rule where appropriate, and substitute in all given values.
6. Solve for the derivative that will give the unknown rate.