How to Multiply a Cosin Wave

In classical mechanics, it's actually a very popular thing, a to multiply in expression. So you multiply an expression or basically make it imaginary. Do the math with the imaginary. Take the real part. You don't never multiply by notno,. But your example made me think of what this is. In this case, oeit is e i, but it is always easier to goimag no, yes. Which is which is which? Wash. Was the whole thing that he was saying, like some some system, some some expressions can be very complicated. Using them together can definitely be very helpful. I mean, yure, gong to learn, i'm hopeful gong