Question

Consider the function \(f(x)=\cos x^{2}\). Then
(A) \(f\) is of period \(2 \pi\)
(B) \(f\) is of period \(\sqrt{2 \pi}\)
(C) \(f\) is not periodic
(D) \(f\) is of period \(\pi\)

Answer 1

Ans: (C)
Hint : \(f(x)=\cos x^{2}, f(x+T)=\cos (x+T)^{2} \neq f(x)\) for any \(x \in R\) and \(T>0 .\) So \(f(x)\) is not periodic