We have been given a function . We are asked to find the formula which gives the x-coordinates of the maximum values for given function.
We know that cosine function oscillates between and 1 that is minimum value of cosine is
and maximum value is
.
We also know that and after period of cosine is
. This means after every
, we will get to
.
So maximum of cosine is , where n is an integer.
Therefore, our required formula is , where,