logarithmic differentiation problem

eiei0

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Feb 28, 2009
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I need help finding dy/dx of y=(x-2)^[sup:2y1ce4kx]x+1[/sup:2y1ce4kx], im not sure how i am supposed to use logs to solve the problem (i know i need them because of the power [sup:2y1ce4kx](x+1)[/sup:2y1ce4kx]
 
\(\displaystyle y=(x-2)^{x+1}\)

Take ln of both sides:

\(\displaystyle ln(y)=(x+1)ln(x-2)\)

Differentiate both sides:

\(\displaystyle \frac{y'}{y}=ln(x-2)+\frac{x+1}{x-2}\)

Solve for y':

\(\displaystyle y'=y\left(ln(x-2)+\frac{x+1}{x-2}\right)\)

Remember that \(\displaystyle y=(x-2)^{x+1}\) and sub it in:

\(\displaystyle y'=(x-2)^{x+1}\cdot\left(ln(x-2)+\frac{x+1}{x-2}\right)\)

See now how to do them?.
 
thank you for being amazingly helpful, may i ask how you write the math like that?
 
That is called LaTex. There is a tutorial on this site as well as all over the web. To see what I typed to make it display that way, click on 'quote' at the upper right corner of my post.
 
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