Purpose
Return value
Arguments
- number - The angle in radians for which you want the tangent.
Syntax
How to use
The TAN function returns the tangent of an angle provided in radians. In geometric terms, the tangent of an angle returns the ratio of a right-triangle's opposite side over its adjacent side. For example, the tangent of PI()/4 (45°) returns the ratio of 1.0.
=TAN(PI()/4) // Returns 1.0
Using Degrees
To supply an angle to TAN in degrees, multiply the angle by PI()/180 or use the RADIANS function to convert to radians. For example, to get the TAN of 60 degrees, you can use either formula below:
=TAN(60*PI()/180)
=TAN(RADIANS(60))
Explanation
The graph of the tangent function, shown above, visualizes the output of the function for angles from 0 to a full rotation corresponding to the range [0, 2π]. The function has two vertical asymptotes within the range [0, 2π] where the output diverges to infinity. The tangent function can be equivalently defined in terms of SIN and COS:
=TAN(θ) = SIN(θ)/COS(θ)
Related functions
SIN Function
The Excel SIN function returns the sine of an angle given in radians. To supply an angle to SIN in degrees, multiply the angle by PI()/180 or use the RADIANS function to convert to radians.
COS Function
The Excel COS function returns the cosine of an angle given in radians. To supply an angle to COS in degrees, use the RADIANS function to convert to radians.
ATAN Function
The Excel ATAN function returns the inverse tangent of a number. The function is the inverse of TAN.
