In the circuit given here, \$D_1\$ is an ideal diode and key \$K_1\$ is ON for a long period of time. Now at time \$t_0\$, key K₁ is opened. Draw the voltage waveform oncapacitor C and find the final steady-state voltage on the capacitor:
I tried using Laplace transform but stuck with a third order transfer function and also I am bit confused about the waveform part. The final voltage will always be 9V, right?