PX153 - I2 - multiple integrals

introduction

• for two variables, $x$ and $y$, divide the volume enclosed by the function, $f(x,y)$, the $x-y$ plane, and the boundaries into a stack of columns
• the integral is given by the sum of the volumes of those columns as we take the number of columns to infinity and their basis area (cross-section) to zero
• it is suppose $f(x,y)$ is continuous, single-valued for $a\le x\le b$ and $c\le y\le d$ , ie: the domain of integration, $R$