I'm new here and need a little help. I'm in the process of teaching myself calculus and ran into this function:

y=(a

^{2}+x

^{2})(a

^{2}-x

^{2})

^{1/2}

I was able to differentiate it down to this:

(a

^{2}-x

^{2})

^{1/2}(a

^{2}+x

^{2})+(x(2x(a

^{2}-x

^{2})

^{1/2}-(x(a

^{2}+x

^{2})/(a

^{2}-x

^{2})

^{1/2}))

The answer to the problem is:

dy/dx=a

^{4}+a

^{2}x

^{2}-4x

^{4}/(a

^{2}-x

^{2})

^{1/2 }My problem is that I don't understand how to get from where I'm at to the correct answer.

Can anyone show me step by step how to get the answer.

Thank you.