Find the derivative of using the following definition:

I tried

but am unclear how to proceed.

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- February 28th 2013, 08:35 AMRagnarokFind derivative using limit definition
**Find the derivative of using the following definition:**

I tried

but am unclear how to proceed. - February 28th 2013, 08:55 AMMINOANMANRe: Find derivative using limit definition
Ragnarok

Substitute z with z=z0+δz and do all the necessary expansions and simplifications .then the denominator will become δz .

factorize the numerator and cancel δz . then the limit will show you the final result that must be 4z0^3-2z0

try it - February 28th 2013, 10:33 AMRagnarokRe: Find derivative using limit definition
Thanks Minoanman, but I was specifically instructed to use the above "alternative" definition of derivative as opposed to the one using . Could anyone help me with the algebra/tell me what I'm doing wrong?

- February 28th 2013, 10:59 AMPlatoRe: Find derivative using limit definition
- February 28th 2013, 11:10 AMRagnarokRe: Find derivative using limit definition
Brilliant, thank you!

- February 28th 2013, 01:10 PMSorobanRe: Find derivative using limit definition
Hello, Ragnarok!

You started correctly . . .

Quote:

I like to break it up into three steps.

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Therefore: . .