# intervals of increasing/ decreasing

• Aug 16th 2009, 05:15 PM
yoman360
intervals of increasing/ decreasing
for $\displaystyle f(x) = x^{1/3}$
increasing: (-∞, ∞)
Decreasing: ?
for decreasing i think its none. idk
• Aug 16th 2009, 05:21 PM
pickslides
What exactly is your function?

Did you mean $\displaystyle y=x^{\frac{1}{3}}$ ?

It will be increasing on $\displaystyle \frac{dy}{dx}>0$ and decreasing on $\displaystyle \frac{dy}{dx}<0$
• Aug 16th 2009, 05:55 PM
yoman360
Quote:

Originally Posted by pickslides
What exactly is your function?

Did you mean $\displaystyle y=x^{\frac{1}{3}}$ ?

It will be increasing on $\displaystyle \frac{dy}{dx}>0$ and decreasing on $\displaystyle \frac{dy}{dx}<0$

I haven't learned that dy/dx stuff yet so that doesn't make sense to me right now. And yes its $\displaystyle f(x)= x^{1/3}$
• Aug 16th 2009, 08:22 PM
pickslides
Quote:

Originally Posted by yoman360
for $\displaystyle f(x) = x^{1/3}$
increasing: (-∞, ∞)

This is correct therefore it cannot be decreasing.