How to do this?

Question

Hi all,
I'm trying to make a function like this f(x)=a from this (http://img148.imageshack.us/img148/5906/mathxj4.gif). Im' not sure if it's possible but....... I really need it! Thanks for your time.

Here is the link of the image again:

http://img148.imageshack.us/img148/5906/mathxj4.th.gif

or

http://img2.freeimagehosting.net/uploads/bf96b3e0bc.gif

Answer 1

I can't get the image.
--------------
Ok, I hope I remember my integrals right...

Integral of e^(-z/2) = -1/2 * e^(-z/2)
So, if you're going from -a to a:

[-1/2 * e^(-a/2)] - [(-1/2)*e^(a/2)]
simplifying that a bit...

(-1/2)[ e^(-a/2) - e^(a/2)]

Oh, and don't forget the 1/(sqrt (2pi))

So, now you have:

x = 1/(sqrt (2pi)) * (-1/2)[ e^(-a/2) - e^(a/2)]

I think that's what you're looking for.

Answer 2

haha! try it your self