Write down the period of the graph of y=3/(2+(cos2x)^2), and also the coordinates of a maximum value of y.

For the second question I answered correctly.

For the first, however I didnt.

It seems obvious to me that the period is 90, due to x being multiplied by 2 and the expression being squared; however the answer is 180.

Its also clear by the graph that the period is 90; is this a typo?