1. The problem statement, all variables and given/known data Hi, I have an electrical circuit, from which I have derived 4 equations to work out the current I of the circuit. To solve I need to put the equations into a matrix and find the eigenvalues & vectors, great I can do that. However there is an additional matrix on the end for voltage values. Previously it was assumed the circuit was DC so all voltages would = 0, as you can see in the picture below. Now its AC and I dont know what to do with the 'extra' matrix as its now a function and has to be considered. This probably makes little sense as I admit alot is going over my head. 2. Relevant equations This picture best describes the situation. https://www.dropbox.com/s/5y2oe359a84f7za/IMG_20141005_202343113.jpg?dl=0 3. The attempt at a solution I can find the eigenvalues for matrix 'A' but I dont know where the extra bit comes into play... Thankyou for any guidance.