Topics: Numerical Analysis - Numerical Method

The secant method is an open numerical method of linear interpolation that can solve equations. It’s similar to the Newton method.


It supposes that is linear, and draws a secant line that passes through and . However, unlike the Newton method and other methods (like the bisection method), the interval and must not necessarily contain a root.

With the help of this image, we can visualise that:

…and from there:

Finally, in general, we have that: