1/h(x+h)^2

1/hx^2

What would you do to make the above rationals NOT be over 1?

Printable View

- Sep 1st 2009, 04:59 PMnautica17How would you undo these?
1/h(x+h)^2

1/hx^2

What would you do to make the above rationals NOT be over 1? - Sep 1st 2009, 05:22 PMskeeter
- Sep 1st 2009, 05:28 PMnautica17
There is no other question. I just want to make what I listed to not be over 1.

The original equation that I am solving is:

((1/h(x+h)^2)-(1/hx^2)) / h

I just wanted to make those two parts in the numerator a little bit more simpler so that they are not fractions. How do I go about doing so? Or is there some other way I can solve. - Sep 1st 2009, 05:48 PMskeeter
- Sep 1st 2009, 06:01 PMnautica17
Yea I did. Then I just multiplied the top and bottom by 1/h after I set up the equation and got to this point. Now I'm stuck. Sorry for lack of info on my part. I have a bunch of homework and I'm trying to multi-task everything right now.

- Sep 1st 2009, 06:04 PMStroodle
- Sep 1st 2009, 06:08 PMnautica17
- Sep 1st 2009, 06:14 PMskeeter
your difference quotient should be ...

$\displaystyle \frac{\frac{1}{(x+h)^2} - \frac{1}{x^2}}{h}$

it can be rewritten as ...

$\displaystyle \frac{1}{h}\left(\frac{1}{(x+h)^2} - \frac{1}{x^2}\right)$

work inside to get a common denominator ...

$\displaystyle \frac{1}{h}\left(\frac{x^2 - (x+h)^2}{x^2(x+h)^2}\right)$

expand the numerator ...

$\displaystyle \frac{1}{h}\left(\frac{x^2 - (x^2+2xh+h^2)}{x^2(x+h)^2}\right)$

combine like terms in the numerator ...

$\displaystyle \frac{1}{h}\left(\frac{-2xh-h^2)}{x^2(x+h)^2}\right)$

factor $\displaystyle -h$ out of the numerator ...

$\displaystyle \frac{1}{h}\left(\frac{-h(2x+h)}{x^2(x+h)^2}\right)$

divide out the h's ...

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

if you have covered limits in class, take the limit as $\displaystyle h \to 0$ and simplify ... - Sep 1st 2009, 06:29 PMnautica17
Thank-you that explains it. :) I guess my tutor at school didn't know what they were doing.