Let f(x)=|x2−1|, then in which of the following interval(s) f(x) is one-one function

Let f(x)=|x2−1|, then in which of the following interval(s) f(x) is

1.	Let f(x)=\|x2−1\|, then in which of the following interval(s) f(x) is one-one function
Answer» Let $f (x) = \| x^{2} - 1 \|,$ then in which of the following interval(s) $f (x)$ is one-one function