wayne

Hi, Given: v=40 cos(100pi t + pi/3) Question: what is the min number of msec that the function must be shifted to the left if the expression for v is 40 cos(100pi t)? therefore I have the equation: 40 cos(100pi (t+t0) + pi/3) = 40 cos(100pi t) hence, 100pi (t+t0) + pi/3 = 100pi t However at that point I decided to check the answers making sure I was on the right track and I was not. According to my book: the equation to start was: 40 cos(100pi (t+t0) + pi/3) = 40 cos(100pi t +2pi) with the 2pi we end up with a t0 positif but the way I did it, t0 is negatif. Is that the reason why they added the 2pi ? Thanks for your answer(s)