q the voltage at terminal a relative to terminal

Question

Q. The voltage at terminal a relative to terminal b of an electric component is v(t) = 20 cos 120πt V. A current i(t) =-4 sin 120πt A ?ows into
terminal a. From time t₁ to t₂, determine the total energy ?owing into the component. In particular, find the energy absorbed when t₂ = t₁ + 1 / 15.