1. The problem statement, all variables and given/known data A 100-W heater is designed to operate with an applied voltage of 120V. a) What is the heater's resistance, and what current does the heater carry? b) Show that if the potential difference V across the heater changes by a small amount ΔV, the power P changes by a small amount ΔP, where ΔP/P = 2ΔV/V. (Hint: Approximate the changes by modeling them as differentials, and assume the resistance is constant. c) Using the part b result, find the approximate power delivered to the heater if the potential difference is decreased to 115V. Compare your result to the exact answer. 2. Relevant equations P = IV = V2/R 3. The attempt at a solution I'm stuck on part b). So far I have ΔP=ΔV2/R ΔP/P=(ΔV/V)2 I'm not really sure what to do.