# FindMinimum [] methods

Which algorithm is used when we do not use the option Method of FindMinimum[] function.

FindMinimum[f,{x,x0}]

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• With Method->Automatic and two starting values, FindMinimum uses Brent's principal axis method. With one starting value for each variable, FindMinimum uses BFGS quasi-Newton methods, with a limited memory variant for large systems.
• If the function to be minimized is a sum of squares, FindMinimum uses the Levenberg-Marquardt method (Method->"LevenbergMarquardt").
• With constraints, FindMinimum uses interior point methods.