๐Ÿ“ˆcollege algebra review

Increasing function

Written by the Fiveable Content Team โ€ข Last updated September 2025
Written by the Fiveable Content Team โ€ข Last updated September 2025

Definition

An increasing function is a function where the value of the output increases as the input increases. Mathematically, for any two values $x_1$ and $x_2$ such that $x_1 < x_2$, the function $f(x)$ satisfies $f(x_1) \leq f(x_2)$.

5 Must Know Facts For Your Next Test

  1. In an increasing function, if $x_1 < x_2$ then $f(x_1) \leq f(x_2)$ holds true.
  2. If the inequality is strict, i.e., $f(x_1) < f(x_2)$ when $x_1 < x_2$, then the function is called strictly increasing.
  3. The slope of the graph of an increasing linear function is always positive.
  4. In calculus terms, if the derivative of a function $f'(x) > 0$ for all $x$ in its domain, then it is an increasing function.
  5. An increasing function may have flat regions where the slope is zero but does not decrease at any point.

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