Chapter 5 - Trigonometric Identities - Section 5.5 Double-Angle Identities - 5.5 Exercises - Page 238: 70b

The maximum wattage is 200.49 The minimum wattage is 0

$W = VI$ $W = (163~sin~120\pi t)(1.23~sin~120\pi t)$ $W = 200.49~sin^2~120\pi t$ The maximum wattage occurs when $sin~120\pi t = 1$. The maximum wattage is $(200.49)(1)^2$ which is 200.49 The minimum wattage occurs when $sin~120\pi t = 0$. The minimum wattage is $(200.49)(0)^2$ which is 0