Question

What is the period of the sinusoidal voltage f(t)=50cos(4πt-30°)?

Answer 1

so it shifts over 30 degrees to start, and it's compressed by a factor of 4pi. The normal period is 2pi, and the compression factor causes one period to to complete in 1/4pi the normal rate. There are barely over 12 cycles in a normal period at that rate. How to solve it algebraically isn't quite as clear for me though, but it's how it works out graphically.