How can I find the period, frequency, and phase shift to problems set up like..
h= -15cos (pie t/3) +21
what if it is like
E= 150cos 80 pie t
I am familiar with solving these equations with. . 360/k and -c/k and all that, but this time around I'm not getting the right results. I thought maybe these problems were set up differently. I sometimes have trouble with working with radians. I don't think these are difficult, but i need to have the right approach. help would be great!