# use l'hospitals rule

• Oct 25th 2012, 08:23 AM
pnfuller
use l'hospitals rule
Attachment 25397i dont even know where to begin with this?
• Oct 25th 2012, 08:36 AM
Plato
Re: use l'hospitals rule
Quote:

Originally Posted by pnfuller
Attachment 25397i dont even know where to begin with this?

Quote:

Originally Posted by pnfuller
Attachment 25397i dont even know where to begin with this?

Actually that can't be done unless it says that $\displaystyle f$ is differentiable.
If we assume that is what the question means then
what if $\displaystyle \frac{d[-f(x-h)]}{dh}=~?$.
• Oct 25th 2012, 08:41 AM
HallsofIvy
Re: use l'hospitals rule
Since the problem says that f' (NOT f) is continuous, I think we can assume that f is differentiable!

pnfuller, since the problem says "use L'Hopitals rule", perhaps you could begin by doing that?
• Oct 25th 2012, 08:51 AM
Plato
Re: use l'hospitals rule
Quote:

Originally Posted by HallsofIvy
Since the problem says that f' (NOT f) is continuous, I think we can assume that f is differentiable!

It does not show $\displaystyle f'$ on this computer.
It could be that the image is so dark.
I wish we could ban posting questions as images.
• Oct 25th 2012, 11:16 AM
pnfuller
Re: use l'hospitals rule
well how do you take the derivative of the numerator with all the different variables?
Quote:

Originally Posted by HallsofIvy
Since the problem says that f' (NOT f) is continuous, I think we can assume that f is differentiable!

pnfuller, since the problem says "use L'Hopitals rule", perhaps you could begin by doing that?