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mark1
Nov19-04, 08:49 AM
The following problem appears in my textbook (before it discusses the quotient or product rule, so those rules cannot be used for the answer):

Find the derivative of the function: \frac{x^3-3x^2+4}{x^2}

I brought the denominator to the top and multiplied it out to get {x-3+4x^-2}[/ltex]. I then took the derivative of that to get [tex]{1-0-8x^-3}, which can be simplified to \frac{-7}{x^3}.

However, in the back of my book, the answer is given as \frac{x^3-8}{x^3}.

Please enlighten me as to where i went wrong.

gnome
Nov19-04, 09:00 AM
Your arithmetic:
1 - \frac{8}{x^3} \neq \frac{-7}{x^3}

mark1
Nov19-04, 09:17 AM
Thanks! For some reason, i did the calculus right but messed up on the algebra. :redface:

gnome
Nov19-04, 09:47 AM
It happens. :smile: