Find the mass of the triangular region with vertices (0, 0), (3, 0), and (0, 1), with density function ρ(x, y)=x2+y2.

Since density is the ratio of mass to (in this case) area, we can find the mass of the triangular region by computing the double integral of the density function over :

The boundary of is determined by a set of lines in the plane. One way to describe the region is by the set of points,

So the mass is

a variable is any characteristics, number, or quantity that can be measured or counted. a variable may also be called a data item. hope i !