Car tires need to be inflated properly because over inflation or under inflation can cause premature tread wear. The datain the table show tire life L (in thousands of miles) for a
certain type of tire at various pressures P (in lbyin2).
(a) Use a calculator to model tire life with a quadratic function of the pressure.
(b) Use the model to estimate dL/dP when P = 30 and when P = 40. What is the meaning of the derivative?
What are the units? What is the significance of the signs of the derivatives?