Question

Determine the intervals on which the function is increasing, decreasing, and constant.

Increasing on x < 0; Decreasing on x > 0

Increasing on x > 0; Decreasing on x < 0

Increasing on all real numbers

Decreasing on all real numbers

Answer 1

@Stiwan?

Answer 2

Look at two different x values, let's call them x and x'. We suppose that x' > x. What is the implication for f(x') and f(x)?

Answer 3

e.g. let x' be 10 and x be -10. What follows for f(10) and f(-10)?