Question

what are the extreme values of Cos 2x + cos square x ​

Answer 1

Answer:

As X tends to be pi or zero the value of Cos X tends to be (-1) or simply 1, both of whose square values are 1. Here when you substitute (n×180) the answer changes between (-1) and 1. But when they are squared the answer become 1. Thus the maximum value of Cos 2X + Cos^2 X is 1+1 = 2.