# Homework Help: Doing fractional superscripts in latex

1. Sep 13, 2010

### NotaPhysicist

1. The problem statement, all variables and given/known data

I know this is the wrong place. I tired to post in Science materials but it wouldn't let me.

Trying to do this in latex

t_n = ar^(n-1)

$$t_n=ar^{n-1}$$

Getting weird results. I'm using Chrome on Vista. Its driving me nuts. I'm trying to post questions. Can someone sort me out?

2. Sep 13, 2010

### cristo

Staff Emeritus
I've edited your post. Click on the equation to see the required input.

3. Sep 13, 2010

### Staff: Mentor

Assuming that you are interested in fractional exponents, here are a couple of ways of doing them. Click on either to see the underlying LaTeX code.

$$e^{x/2}$$
$$e^{\frac{x}{2}}$$

4. Sep 14, 2010

### NotaPhysicist

Thank you for doing that.

5. Sep 14, 2010

### HallsofIvy

In other words use { and } to group things you want all in the same superscript (or subscript or numerator or ...). If you actually want a "{" or "}" as, for example, in designating sets, use \{ and \}.

6. Sep 15, 2010

### NotaPhysicist

The problem had turned out to be the browser. Once I write some latex markup and click "preview", I get my first look at the result. Subsequently if I want to see revisions after clicking "preview" again, I have to refresh the page. Otherwise I see the old markup in the newly reviewed page. It will even show the markup from the last post if I don't refresh. So whatever edits I was doing to the markup, it wasn't showing up in my browser until I refreshed the page.

Using Chrome on Vista. Probably a cache problem. Does anyone else have this problem?

7. Sep 15, 2010

### ehild

Yes, the same problem. I use Mozilla and windows XP. Nothing helps. When I post it, the Latex code is usually correct. But it is impossible to edit. I have to remove and type in again.

ehild

8. Sep 15, 2010

### diazona

I think everyone has this problem. It's really the PF server's fault, since the server sends HTTP headers directing browsers to cache all images in a post preview for a week, and then it reuses the same URLs even if the LaTeX code changes. So there's no way to get around it without disabling the cache, or refreshing the page. (In Firefox, you can right click on an image, control-click "View Image" which will open it in a new tab, and then refresh that without having to refresh the whole page)