The SEC function in Excel calculates and returns the secant of a given radians. The Secant is the reciprocal of Cosine.

SEC(θ) = Hypotenuse **/ **Adjacent = **c/b**

Secant of the angle θ, is the ratio of the hypotenuse side – c, to the adjacent side – b.

**Syntax of SEC Function in Excel**

SEC(number)

Where Argument number is angle in radians which you need to calculate the Secant of.

**NOTE:** If your angle is in degrees, you will need to convert it into radians before supplying it to the SECANT Function with the help of Radians function

=RADIANS( degrees )

**Example of SEC Function in Excel**

**Formula**

- In Row number 2 and 3 the radians value is passed to the SEC Function
- In row number 4, Angle 60 degree is converted to radians and passed as input to the SEC Function.
- In Row number 5 Radians -π/6 is passed as input to the SEC Function.
- In row number 6, Angle -90 degree is converted to radians and passed as input to the SEC Function.