Let's take [itex]y=x^2[/itex] as an example. This function decreases if [itex]-\infty < x < 0[/itex] and increases if [itex]0 > x > \infty[/itex]. But what about [itex]x=0[/itex]? Shouldn't it be included in one of the two ranges of [itex]x[/itex]?(adsbygoogle = window.adsbygoogle || []).push({});

- Kamataat

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Increasing/decreasing f(x)

**Physics Forums | Science Articles, Homework Help, Discussion**