finverse

Functional inverse

Syntax

g = finverse(f)

g = finverse(f,var)

Description

g = finverse(f) returns the inverse of function f, such that f(g(x)) = x. If f contains more than one variable, use the next syntax to specify the independent variable.

g = finverse(f,var) uses the symbolic variable var as the independent variable, such that f(g(var)) = var.

Examples

Compute Functional Inverse

Compute functional inverse for this trigonometric function.

syms x
f(x) = 1/tan(x);
g = finverse(f)

g(x) =
atan(1/x)

Compute functional inverse for this exponential function by specifying the independent variable.

syms u v
finverse(exp(u-2*v), u)

ans =
2*v + log(u)

Input Arguments

f — Input

symbolic expression | symbolic function

Input, specified as a symbolic expression or function.

var — Independent variable

symbolic variable

Independent variable, specified as a symbolic variable.

Limitations

• finverse does not issue a warning when the functional inverse is not unique.

Version History

Introduced before R2006a