First step to finding the derivative of 20x/(x^2-4)^2

Limits, differentiation, related rates, integration, trig integrals, etc.
Cafe au lait
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First step to finding the derivative of 20x/(x^2-4)^2

Postby Cafe au lait » Tue Jan 04, 2011 3:38 am

I got f'(x)=[(x^2-4)^2(20)-2(x^2-4)(2x)(20x)]/(x^2-4)^4
=(-80x^4+340x^2-80)/(x^2-4)^3
and simplify

But I am pretty sure my first step was wrong, like I did the chain or product rule wrong because my answer does not match up to what my TI-89 says it is supposed to be.

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Martingale
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Re: First step to finding the derivative of 20x/(x^2-4)^2

Postby Martingale » Tue Jan 04, 2011 4:09 am

Cafe au lait wrote:I got f'(x)=[(x^2-4)^2(20)-2(x^2-4)(2x)(20x)]/(x^2-4)^4
=(-80x^4+340x^2-80)/(x^2-4)^3
and simplify

But I am pretty sure my first step was wrong, like I did the chain or product rule wrong because my answer does not match up to what my TI-89 says it is supposed to be.












Cafe au lait
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Joined: Mon Jan 03, 2011 11:02 pm
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Re: First step to finding the derivative of 20x/(x^2-4)^2

Postby Cafe au lait » Tue Jan 04, 2011 5:48 am

That's the answer my calculator gave me! Very helpful, thank you.

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Martingale
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Re: First step to finding the derivative of 20x/(x^2-4)^2

Postby Martingale » Tue Jan 04, 2011 5:52 am

Cafe au lait wrote:... to what my TI-89 says it is supposed to be.



Cafe au lait wrote:That's the answer my calculator gave me! ...



I know. You are not the only one with a ti-89 :wink:


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