The COS function in Excel calculates and returns the cosine of a given radians.
COS(θ) = Adjacent / Hypotenuse = b/c
Cosine of the angle θ, is the ratio of the adjacent side – b, to the hypotenuse – c.
Syntax of COS Function in Excel
COS(number)
Where Argument number is angle in radians which you need to calculate the cosine of.
NOTE: If your angle is in degrees, you will need to convert it into radians before supplying it to the COS Function with the help of Radians function
=RADIANS( degrees )
Example of COS Function in Excel
Formula
- In Row number 2 and 3 the radians value is passed to the COS Function
- In row number 4, Angle 60 degree is converted to radians and passed as input to the COS Function.
- In Row number 5 Radians -π/6 is passed as input to the COS Function.
- In row number 6, Angle -90 degree is converted to radians and passed as input to the COS Function.