Differentiation Application

This problem has been proving extremely tough for me. Thanks a lot for the help.

The period of a pendulum is given T=2(Pi)Squareroot(L/G) where L is the length of the Pendulum in feet, g is the acceleration due to gravity and T is the time in seconds. Suppose that the pedulum has ben subjected ton an increase in temeprature such that the length has increased by 1/2%.

a) Find the approximate percent change in the period.

b) Using the result in part (a), find the approximate error in this pendulum clock in one day.