# Function tan Calculate the tangent of a value. `tan(x)` is equal to `sin(x) / cos(x)`. For matrices, the function is evaluated element wise. ## Syntax ```js math.tan(x) ``` ### Parameters Parameter | Type | Description --------- | ---- | ----------- `x` | number | BigNumber | Complex | Unit | Array | Matrix | Function input ### Returns Type | Description ---- | ----------- number | BigNumber | Complex | Array | Matrix | Tangent of x ### Throws Type | Description ---- | ----------- ## Examples ```js math.tan(0.5) // returns number 0.5463024898437905 math.sin(0.5) / math.cos(0.5) // returns number 0.5463024898437905 math.tan(math.pi / 4) // returns number 1 math.tan(math.unit(45, 'deg')) // returns number 1 ``` ## See also [atan](atan.md), [sin](sin.md), [cos](cos.md)