Hi please help deriving this question:see the image for the equation. deriv.bmp
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i do know that one of the rules involving natural logarithms is: y=lnx which derived is y'= 1/x . But I'mstill not sure. This is my teacher's solution:y'= -5-3x^2 / (-5-5x-x^3)
derivative of ln(x) is y' = 1/(x)*(x)'
y'= (ln(-5-5x-x^3))'*(-5-5x-x^3)' so, you have 1/(-5-5x-x^3)*(5x-3x^2) =(5x-3x^2)/(-5-5x-x^3)
Last edited by dokrbb; April 17th 2013 at 11:03 AM.
Reason: added the rule
If y is the log of a function of x
Substitute for the function in the log and use the chain rule.
Let u= g(x), then
So for your problem
Last edited by Shakarri; April 17th 2013 at 12:33 PM.
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