Normalizing wave functions calculator issue

[Galgenstrick]

This is more of a calculator issue than the physics part. Below is just an example from my textbook. Our professor expects us to be able to plug an integral like this into our calculator to get the answer. although every problem I have tried like this just pops out another integral on the calculator. I am using a TI-89 and Voyage 200, both won't solve the integral. I am not sure if there is some setting I am missing to be able to do this. Can someone please try this out? Thanks!

Homework Statement

What is the value of A if if this wave function is normalized.

$$\psi$$ (x)=A*e $$^{-ax^2}$$

Homework Equations

$$\int$$ $$\psi$$ (x) $$^{2}$$ dx = 1 from -infinity to infinity

The Attempt at a Solution

The solution is (2a/Pi)^(1/4). (this was an example problem in the textbook)

 

[kuruman]

I don't have much experience with the calculators you mentioned, but have you tried doubling the integral and integrating from zero to +infinity?