Question

For f(x) = x^1/3, f(x) is not differentiable at x=___?
hint: try to find the derivative by using the definition

Answer 1

\[f'(x)=\frac{1}{3}x^{\frac{1}{3}-1}=\frac{1}{3x^\frac{2}{3}}\]
when is the bottom zero?

Answer 2

when x=0?