In numerical analysis, Ridders' method is a root-finding algorithm based on the false position method and the use of an exponential function. The method is due to C.Ridders.

Ridders' method is simpler than Muller's method or Brent's method but with similar performance. The formula below converges quadratically when the function is well-behaved, which implies that the number of additional significant digits found at each step approximately doubles; but the function has to be evaluated twice for each step, so the overall order of convergence. If the function is not well-behaved, the root remains bracketed and the length of the bracketing interval at least halves on each iteration, so convergence is guaranteed.

Method

is determined by

,

The iterative procedure can be terminated when a target accuracy is obtained.

A Ridders' method is a numerical root-finding algorithm used to find a zero of a continuous function. It's an iterative method that combines the false position method with an exponential function to converge on a root. The method is generally considered simpler and performs similarly to other popular methods like Muller's or Brent's methods.

References