I always have difficulties with fractions...

Find the derivative of f(x) = (x/x+1) - 3

I usually break it down to f(x) = x/x +x/1 -3

f'(x) = 1 + 1

I know that's not right...please help.

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- Aug 7th 2006, 08:37 PMbeckyderivatives
I always have difficulties with fractions...

Find the derivative of f(x) = (x/x+1) - 3

I usually break it down to f(x) = x/x +x/1 -3

f'(x) = 1 + 1

I know that's not right...please help. - Aug 7th 2006, 08:47 PMThePerfectHackerQuote:

Originally Posted by**becky**

Now,

Thus, using the generalized power rule,

- Aug 7th 2006, 08:47 PMSoroban
Hello, becky!

Quote:

Find the derivative of:

I usually break it down to:*. . . I hope not!*

What's wrong with using the Quotient Rule?

- Aug 7th 2006, 08:50 PMSoltras
Hi Becky

You can only break up a fraction if the added terms are on top, not bottom.

So while , it's not true that .

So we can't use that kind of techniue in this particular situation.

What you want to do here is apply the quotient rule, which basically says that if and are differentiable functions, then .

In your case, is the top of the fraction and is the bottom, .

So and .

Then

- Aug 7th 2006, 09:06 PMbeckyThanks for your help
You all explain it so much better than a textbook.