In the circuit shown in Figure $4,$ a generator supplies a voltage of $E(t)=40 \sin 60 t$ volts, the inductance is $1 \mathrm{H},$ the resistance is $20 \Omega,$ and $I(0)=1 \mathrm{A}$ .
(a) Find $I(t)$ .
(b) Find the current after 0.1 s.
(c) Use a graphing device to draw the graph of the current function.