## Electrical Engineering: Principles & Applications (6th Edition)

Power delivered to the resistor is: $p(t)=v^2(t)/R=48\cos^2(2\pi t)=24+24\cos(4\pi t)$ Then to find energy delivered: $w=\int_0^2 p(t)dt=\int_0^2 24+24\cos(4\pi t)dt =[24+\frac6\pi\sin(4\pi t)]_0^2=48J$