Question

I'm having difficulty conceptually understanding how to covertand solve a derivative with a radical function.

Take this question for example:http://cl.ly/image/1U1L2s1J2J1k

I don't understand how to convert the radical fraction into auser friendly form. The answer is:http://cl.ly/image/1M3Q0Z0e043A

I'm having difficulty seeing how this happens...I was thinkingthe first fraction turns out to thishttp://cl.ly/image/1c0x23100z1s but that'sdefinitely not right.

If someone can point me in the right direction, I'd muchappreciate it!