Observe the circuit:

The input sine voltage is .

Compare the function with .

Here .

and are in parallel.

is in series with .

can be written in polar form is .

(b)

Step 1:

The input sine voltage is .

Compare the function with .

in polar form can be written as .

The sine voltage can be written as 

From (a): Total impedance .

Find the total current.

Total current is 

Step 2:

Find the capacitor.

can be written in polar form as .

Find the voltage across the capacitor.

Current across the capacitor is  V.

(c)

Step 1:

From part (b): The input sine voltage is

in complex form can be written as

and are in parallel, hence voltage across resistor and inductor is same.

From (b): Voltage across the capacitor is  V.

in complex form can be written as

Current across the capacitor is  V.