SEC function
Description
Secant function. SEC(x) returns the secant of x. The argument x must be expressed in radians. To convert degrees to radians you use the RADIANS function.
The secant is the reciprocal of the cosine:
$$ \operatorname{sec}(x) = \frac{1}{\operatorname{cos}(x)} $$
The argument x can be a real number or a matrix. When it is a matrix, the function returns a matrix with the same dimensions and with the SEC function applied to all elements.