Chapter 17, Problem 43P

The voltage across the terminals of a circuit is

$\begin{array}{l}v(t)=[30+20\cos (60\pi t+45°)\\ +10\cos (120\pi t-45°)]\text{}\text{V}\end{array}$

If the current entering the terminal at higher potential is

$\begin{array}{l}i(t)=6+4\cos (60\pi t+10°)\\ -2\cos (120\pi t-60°)\text{A}\end{array}$

find:

1. (a) the rms value of the voltage,
2. (b) the rms value of the current,
3. (c) the average power absorbed by the circuit.