Step 1:

Observe the circuit:

The input sine voltage is .

Compare the function with .

Here , , .

,  are in parallel.

.

and are in series.

The total impedance is .

.

can be written in polar form is .

The total impedance is .

(b)

Observe the circuit:

The input sine voltage is .

Compare the function with .

in polar form can be written as .

.

The sine voltage can be written as .

can be written in complex form is .

From (a):

The total impedance is .

Find the total current.

The total current is .

.

Find .

Fom (a): .

A parallel network has same voltage across each element.

 can be written in polar form is .