I am working on a RL circuit problem and am having some trouble. I will list the steps I have gone through and see if you can help me out. This is how our professor should us how to solve these problems using the step by step method. http://imagizer.imageshack.us/v2/640x480q90/534/fokx.png Step 1: k1+k2e^(-t/tau) Step 2: First solve for Vo(0-) To do this I short circuited the inductor and used three loop equation to solve for I1, I2 and I3 respectively 7I1 + 3I3 = 12 2I2 = 12 3I1 + 9I3 = 0 so respectively we have I2 = 6A and we can solve for I1 and I3 to find I1 = 2A and I3 = -2/3A and we can use that to find Il(t) will equal 20/3 since Il(t) = (I2 - I3) we can also solve for V(0-) and that would be 2I1 = 4V Step 3: Solve for Vc(0+) This is where I start running into problems I believe. Now we can replace the short circuit with the current for Il(t) since Il(0-) = Il(0+) and since the switch closes we have a new circuit. Now I came up with 4 different equation using loop analysis and got 4I1 + 4I2 = 0 4I1 + 7I2 + 3I4 = 12 2I3 = 12 3I2 + 9I4 = 0 now when I solve for the currents I get I1 = -6A I2 = 6A I3 = 6A I4 = -2A now this does not seem right one because (I2 - I3) should equal 20/3 and because when you use these values to calculate Vo(0+) our value comes out to 0V but i am not sure where I went wrong. Any help would be appreciated. Thank you.