I am working on this circuit:
Basically, \$V_1\$ is on all the time, and \$V_2\$ turns on at \$t=0\$. For the conditions at \$t=0^-\$ (the time just before zero), I can see why the voltage across the capacitor is equal to \$V_1\$. The current through the resistor at \$t=0^-\$ is zero, as no current would flow.
After the second voltage source turns on, my sources tell me that the current flowing through \$C\$ is equal to \$V_2 / R_2 \$. That is, the current instantaneously goes from 0 to \$V_2 / R_2 \$ at \$t=0\$.
What is going on here?