What is the period and amplitude and frequency for #s = 3 cos 5t#?

1 Answer
May 5, 2015

cosinus oscillates between 1 and -1 so of you are multipliying it by 3 it oscillates between 3 an -3, you amplitude is 3 .
#cos(0)=cos(2pi)# this is the condition for a cycle. so for your equation #cos(5·0=0)=cos(5·t=2pi)# you have to solve 5t=2pi which solution is # t=2pi/5# after this t you've made a complete cycle so t is the period