Step1:

Circuit current is .

Find the voltage using waveform given.

Observe the graph: 

Voltage in is .

For :

Current across the inductor .

Observe the circuit, H. \ \

.

Find the constant value at the initial conditions.

At , .

.

.

Step 2:

For :

Current across the inductor .

Observe the circuit, H. \ \

.

.

Find the constant value at the initial conditions.

At , .

.

.