Showing function of two variables is increasing

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So I have the function $f(x,y(x)) = \sqrt{|x(1-y(x)^2)|}$ and I want to show that it is an increasing function of $x$ for $y\neq1$ and for $x\geq0$. So what I did first was split into two cases where $1-y(x)^2$ is postive and negative respectively. Then I took the total derivative of $f(x,y(x))$ and tried to show it was positive. But when I done this I kept having a $y'(x)$ crop up which I have no information about so couldn't reach the required conclusion. Am I going along the right path?