Difficult# Functions and Inverses

APCALC-Y8LLHY

For which of the following functions are both the original function and its inverse increasing for all $x \ne 0$?

I.$ f( x ) =\sqrt { |x|} $II.$ f( x ) =- \cfrac {1}{x}$III.$ f( x ) ={ x }^{ \frac{1}{3}}$