Mathematica issue with definite integrals

[RTourn]

Homework Statement

I'm trying to evaluate the problem below but the Mathematica gives me is in terms of x. Can someone please help me solve this thing.

Homework Equations

Integrate[((2*A)(E^(-d*((m*x^2)/h) ) ) )^2,x,{x,0,Infinity} ]

The Attempt at a Solution

The solution Mathematica gives me is (a^2 Sqrt[2 \[Pi]] x)/Sqrt[(d m)/h]
Why is there an "x" in the solution at all?
I'm using Mathematica 6.030

 

[praharmitra]

u want to solving a definite integral where x varies from 0 to infinity...

i think the function for definite integration is DIntegrate. integrate just gives u indefinite integration

 

[qntty]

This is how the input should look. Putting an x after the expression tells it to antidifferentiate.

Integrate[((2*A)(E^(-d*((m*x^2)/h) ) ) )^2,{x,0,Infinity}]

 

[RTourn]

@qntty Thanks it worked!