I need help finding the derivative of this. I am a bit confused. I have y = (x^2)/(x^2+3). the derivative is 6x/(x^2+3)^2. I understand the quotient rule, and how they got the squared on the bottom. but how did they get the 6x on the top?

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- Jun 13th 2012, 11:24 AMdroidusfinding derivative
I need help finding the derivative of this. I am a bit confused. I have y = (x^2)/(x^2+3). the derivative is 6x/(x^2+3)^2. I understand the quotient rule, and how they got the squared on the bottom. but how did they get the 6x on the top?

- Jun 13th 2012, 11:51 AMReckonerRe: finding derivative
- Jun 13th 2012, 01:14 PMdroidusRe: finding derivative
ok - here is what i get for the second derivative then...

[(x^2 + 3)^2 + 6 - 6x(4x)] / (x^2+3)^4 - Jun 13th 2012, 01:29 PMReckonerRe: finding derivative
The derivative of is not And shouldn't you be multiplying that 6 instead of adding it? Let's be more careful:

Make sure that you're using the chain rule properly. We must remember to differentiate the "inner" function after we differentiate the "outer" function of a composite function.