Problems 21 and 22.
Hint for Problem 7.22:
Combine the series capacitors into an equivalent capacitor.
Refer to Section 6.3 to determine the 
initial voltage on the equivalent capacitor.
Then find i(t), which will allow you to find 
v1(t) and
v2(t).
You will find that for large t, 
the voltages v1(t) and
v2(t) do not approach 0, and this
leads to "trapped" energy.