# The product rule with square roots

I am suppose to find the derivative of $H(u) = (u - \sqrt{u})(u - \sqrt{u})$

I know the formula is the derivative of the second function times the first function plus the derivative of the first function times the second function.

I know that it will be $(1-(1/2) u^{-1/2})(1-(1/2) u ^{-1/2})$ I am pretty certain my problem comes from trying to multiply the $(1/2)u^{-1/2}$ term with itself. What exactly happens? I am getting$(1/2)u^{-1/2}$ I am pretty bad at math so I probably made some simple error. All together I get that the derivative is $2u - u^{-1/2} +1$

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The function you have as what you know "it will be" is incorrect. – Arturo Magidin Sep 20 '11 at 19:48
I edited my submission, if you think something is wrong just please say. – user138246 Sep 20 '11 at 19:48