C. Trapezium rule for integration

The trapezium rule is a numerical method for integration of a function between two bounds.

Other methods exist which are better than the trapezium rule, e.g. Simpson's rule. You can read more about them in text books or on the web.

Why would you want to integrate numerically rather than analytically? Here are two reasons:

• the function cannot be integrated analytically;
• you have a lot of integrations to perform, so some automated process is preferable.