# Function unaryMinus Inverse the sign of a value, apply a unary minus operation. For matrices, the function is evaluated element wise. Boolean values and strings will be converted to a number. For complex numbers, both real and complex value are inverted. ## Syntax ```js math.unaryMinus(x) ``` ### Parameters Parameter | Type | Description --------- | ---- | ----------- `x` | number | BigNumber | Fraction | Complex | Unit | Array | Matrix | Number to be inverted. ### Returns Type | Description ---- | ----------- number | BigNumber | Fraction | Complex | Unit | Array | Matrix | Returns the value with inverted sign. ### Throws Type | Description ---- | ----------- ## Examples ```js math.unaryMinus(3.5) // returns -3.5 math.unaryMinus(-4.2) // returns 4.2 ``` ## See also [add](add.md), [subtract](subtract.md), [unaryPlus](unaryPlus.md)