Find the derivative of f'(-1) when f(x)=(x+4/x)^2

Question

anonymous · Answer

derivative of (blah)^2 = 2(blah) * derivative of blah

anonymous · Answer

wrong JamesWolf the derivative of f(x)=((x+4)/x)^2 is actually f'(x)=                   -(8(x+4))/x^3

anonymous · Answer

james please get off of my question thanks

anonymous · Answer

sure.

anonymous · Answer

http://www.wolframalpha.com/input/?i=derivative+of+%28%28x%2B4%29%2Fx%29%5E2

anonymous · Answer

just out of interest, you need to use the chain rule, then the quotient rule. :)

anonymous · Answer

Lrod, there are rules against just giving the answer, and not showing the method

anonymous · Answer

yes you have to use the quotient rule

anonymous · Answer

plus the chain rule, hence my original post

derivative of (blah)^2 = 2(blah) * derivative of blah

where blah is a friendly term for a function.

the quotient rule is needed after that

anonymous · Answer

well you cant really say blah either :P but yes chain and quo.

anonymous · Answer

I may have misread and thought you only said 2* the original equation. I am sorry for that

anonymous · Answer

no problem

anonymous · Answer

I wont use blah again :)

anonymous · Answer

do you need any help with either of the rules sandy?

anonymous · Answer

yeah sorry i must have overlooked that portion lol. You still with us Sandy?