Question

What is a double integral?

Answer 1

The easiest way to think of a double integral is as the volume under a surface in 3-dimensional space. This is analogous to thinking of a normal integral as being the area under a curve.

If `z = f(x,y)`
then
`int_y int_x (z)` `dx dy` would be the volume under those points, `z`, for the domains specified by `y` and `x`.