- #1

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I'm getting into a little trouble when differentiating polynomial functions.

How do you differentiate

f(x)=ax+b/cx+d ?

Is there other ways of calculating this apart from the chain rule ?

Thanks for any help.

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- Thread starter Duane
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- #1

- 8

- 0

I'm getting into a little trouble when differentiating polynomial functions.

How do you differentiate

f(x)=ax+b/cx+d ?

Is there other ways of calculating this apart from the chain rule ?

Thanks for any help.

- #2

HallsofIvy

Science Advisor

Homework Helper

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- #3

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Sorry I messed up.

What I meant was a "rational" function.

Are "rational" and "quotient" synonymous ?

By applying the quotient rule, I get

(ax+b/cx+d)'= [(cx+d)(ax+b)'-(ax+b)(cx+d)'] / (cx+d)^2

= [a(cx+d)-c(ax+b)] / (cx+d)^2

how to proceed ?

- #4

Stephen Tashi

Science Advisor

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A point about notation, you should write the original function as (ax+b)/(cx+d) to mean [itex] \frac{ax+b}{cx+d} [/itex] instead of writing it as (ax +b/cx + d}, which means [itex] ax + \frac{b}{c} x + d [/itex].

Better yet, look at the sticky thread:

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LaTeX Guide: Include mathematical symbols and equations in a post

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