Integration is often introduced as the reverse process to differentiation, and has wide applications, for example in finding areas under curves and volumes of solids. This section explains what is meant by integration and provides many standard integration techniques.

# Integration using trigonometric formulae

Sometimes integrals involving trigonometric functions can be evaluated by using trigonometric identities. These allow the integrand to be written in an alternative form which may be more amenable to integration. Trigonometric formulae can also be used in substitutions to simplify complicated integrals. Video tutorial 39 mins.