Double Integral Approximation

This was made at George Mason University for Math493: Mathematics Through 3D Printing, taught by Dr. Evelyn Sander.

Gives the double integral approximation for the function f(x,y) = 2*e^(-x^2-y^2), the Gaussian curve in 3 dimensions, using 100, 225, and 400 rectangular prisms, respectively on the interval [-2,2.5]x[-2,2]. The Mathematica code used to generate these models was based on Raouf Boules', Geoff Goodson's, Ohoe Kim's and Mike O'Leary's Calculus III Lab at Towson University, found here: http://www2.stetson.edu/~wmiles/coursedocs/Fall_05/MS_203/calc3labs/Calculus%20III%20-%20Lab%209.htm.

The integral approximator (code provided below) takes a function f on an interval [a1,b1]x[a2,b2] with n discretization points in both the x and y directions, therefore approximating the area under the function with n^2 rectangular prisms (cuboids in Mathematica). Just like in the 1-dimensional integral approximation methods, deltaX = (b1-a1)/n and deltaY = (b2-a2)/n. The x and y coordina