A simple electrical circuit consists of a constant resistor R, a constant inductor L, and an electromotive force source E(r). According to Kirchoff's Second Law, the current i in the circuit satisfies the equation L=di/dt +Ri=E(t). Solve the  differential equation by proving the value of the constant C is:

 C=22/3( 24π/(1+576π^2))

 if given E(t)=110sin120πt, L=3, R=15 and i=0 when t=0 . Then, determine the value of current i when t = 1.