The fMax( Command

Command Summary

Calculates the local maximum of a function.

Command Syntax


Menu Location

While editing a program, press:

  1. MATH to open the math menu
  2. 7 or use arrow keys to select

Calculator Compatibility


Token Size

1 byte

fMax(f(var),var,lo,hi[,tol]) finds the value of var between lo and hi at which the maximum of f(var) occurs. tol controls the accuracy of the maximum value computed. The default value of tol is 10-5.

fMax( only works for real numbers and expressions. Brent's method for optimization is used for approximating the maximum value.


Keep in mind that the result is the value of var, and not the value of f(var). In this example, .7853995667 is not the highest possible value of sin(X)cos(X), but rather the X-value at which sin(X)cos(X) is the highest.

Error Conditions

  • ERR:BOUND is thrown if the lower bound is greater than the upper bound.
  • ERR:DOMAIN is thrown if tol is 0.
  • ERR:TOL NOT MET is thrown if the tolerance is too small for this specific function.

Related Commands


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