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by **isaiah45798** on Mon Jul 18, 2011 7:31 am

how would i evaluate f(x+h)-f(x)/h and simplify if f(x)=x^2-2x. Please help.

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by **Martingale** on Mon Jul 18, 2011 5:07 pm

isaiah45798 wrote:how would i evaluate f(x+h)-f(x)/h and simplify if f(x)=x^2-2x. Please help.

$\frac{f(x+h)-f(x)}{h}=\frac{(x+h)^2-2(x+h)-(x^2-2x)}{h}$

$=\frac{x^2+2xh+h^2-2x-2h-x^2+2x}{h}$

$=\frac{2xh+h^2-2h}{h}$

$=\frac{h(2x+h-2)}{h}$

$=2x+h-2$

by **isaiah45798** on Tue Jul 19, 2011 2:53 am

thankyou

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