$($a$)$ find the coupling coefficient$($b$)$ calculate vo$,($c$)$ determine the energy stored in the coupled inductors at t $=2$ s$.$ THE FINAL ANSWERS ARE $($a$)0\mathrm{.}3535,($b$)0\mathrm{.}3217$ cos$(4$t $+57\mathrm{.}6)$ V$,($c$)1\mathrm{.}168$ J Please explain the necessary steps to solve.