SEC Function in Excel – Usage with Examples

Previously, we implemented the COS Function. In this blog, we would learn the fundamentals of the SEC Function. It is an important type of Trigonometric Function. The function helps us in finding the trigonometric ratio.

So let us begin.

When to Use SEC Function?

The word SEC represents Secant Trigonometric Ratio. The SEC function finds the value of the Trigonometric ratio Secant x where the angle x is supplied in radians. If we have the angle in degrees then we can use any of the following two methods for converting the angle from degrees into radians.

• RADIANS() -The RADIANS function in excel converts an angle from degrees into radians.
• PI() – The PI Function returns the value of the constant π.

If your angle is in degrees then the formula would multiply it by PI()/180° and after that, it will be converted into radians. Let’s take an example if you wanna convert 30° into radians then the formula would be

=30*PI()/180 

which will equal to 1.15 (approx).

Syntax and Arguements

=SEC(number)

The following points will explain the required function argument by the SEC function in Excel.

• number – This is the actual angle corresponding to which we want to get the value of the trigonometric ratio secant. It must be supplied in radians.

Important points to note about the SEC function

Some important points are given below to note about the SEC function

• The number argument must be supplied in radians. We can use any of the two methods to convert an angle from degrees into radians.
• The result of the SEC function is equal to the inverse of the COS function.
• It came into existence in Excel 2013
• The SEC function returns the Secant of an angle provided in radians.
• The graph of Secant x contains two vertical asymptotes at angles π/2 and 3π/2

Examples to Implement SEC Function in Excel

Let us say we have the following list of angles for which we want to find the Secant trigonometric ratio.

Now use the following formula in column B to get the angle converted from degrees to radians with the help of the PI() Function.

=A2*PI()/180

Use the formula in B2 and copy the same.

We can also use the RADIANS Formula in column C.

=RADIANS(A2)

Since we got the angle converted into radians, we can use it in the SEC formula. Use any of the two formulas in column D.

=SEC(B2)

or

=SEC(C2)

As a result, the function returns the value of the trigonometric ratio Secant θ.

This brings us to end.

Thank you for coming.