AC Nodal Analysis Adding source phase angles AFTER calculation?

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Just to clarify the title... Basically for the below circuit we are required to find Vth, Rth and Vo. However, the method of solving this problem is a little strange to me, because as you can see, the source has a phase angle of 30 degrees. The solution to this problem basically says (to find Vth), ignore the 30 degree phase angle, and jam it back onto the final solution at the very end. Ie, solve the circuit with the phase angle from the source equal to 0, and add it back at the very end.

http://img577.imageshack.us/img577/6463/ecquestion.png Something doesn't seem quite right, because I can't actually get my answer computed with everything in place to equal the answer with the angle added in later.

So what I really want to ask is, is this a valid method of solving the equation or not? Any help would be appreciated.

 

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Nevermind... I confirmed this actually does work. For some reason I was setting Io equal to (V1-20)/4 instead of (20-V1)/4. I seemed to have not taken into account the current direction.