Question

Prove that the function f given by f(x) = x² − x + 1 is neither strictly increasing nor strictly decreasing on (−1, 1).

Answer 1

The given function is f(x) = x² − x + 1.

The point 1/2 divides the interval (−1, 1) into two disjoint intervals

Hence, f is neither strictly increasing nor decreasing in interval (−1, 1).