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.

# Finding areas by integration

In simple cases, areas can be found by evaluating a single definite integral. Sometimes the integral gives a negative answer, and sometimes the correct answer can be obtained only by splitting the area into several parts and adding and subtracting appropriately. Video tutorial 45 mins.