ABSTRACT
Double and triple integrals have engineering applications in finding areas, masses and forces of two-dimensional regions, and in determining volumes, average values of functions, centres of mass, moments of inertia and surface areas. A multiple integral is a type of definite integral extended to functions of more than one real variable. This chapter explains how to evaluate double and triple integrals and completes the many techniques of integral calculus. It is seen from the procedure that to determine a double integral people start with the innermost integral and then work outwards. Double integrals may be used to determine areas under curves, second moments of area, centroids and moments of inertia. Determining double integrals is demonstrated in the worked problems. It is seen from the procedure that to determine a triple integral people start with the innermost integral and then work outwards.
