You don't. I presume you have an answer. Would you care to share it with us?How do I delete a question
If someone else is looking at this and wondering as you did, my hint would be to do something equivalent to adding fractions using a common denominator. You could also think of it as factoring out a common factor.I need to prove:
[math](1+x^2)^{-\frac{1}{2}}-x^2(1+x^2)^{-\frac{3}{2}}=(1+x^2)^{-\frac{3}{2}}[/math]
But I dont know where to even begin as the exponents are different.