# Documentation

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# sec

## Syntax

• Y = sec(X)
example

## Description

example

Y = sec(X) returns the secant of the elements of X. The sec function operates element-wise on arrays. The function accepts both real and complex inputs. For real values of X in the interval [-Inf, Inf], sec returns real values in the interval [-Inf ,-1] and [1,Inf]. For complex values of X, sec returns complex values. All angles are in radians.

## Examples

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Plot the secant over the domain and .

x1 = -pi/2+0.01:0.01:pi/2-0.01; x2 = pi/2+0.01:0.01:(3*pi/2)-0.01; plot(x1,sec(x1),x2,sec(x2)), grid on 

Calculate the secant of the complex angles in vector x.

x = [-i pi+i*pi/2 -1+i*4]; y = sec(x) 
y = 0.6481 + 0.0000i -0.3985 + 0.0000i 0.0198 - 0.0308i 

## Input Arguments

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Input angle in radians, specified as a scalar, vector, matrix, or multidimensional array.

Data Types: single | double
Complex Number Support: Yes

## Output Arguments

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Secant of input angle, returned as real-valued or complex-valued scalar, vector, matrix or multidimensional array.

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### Secant Function

The secant of an angle, α, defined with reference to a right angled triangle is

The secant of a complex angle, α, is

$\text{sec}\left(\alpha \right)=\frac{2}{{e}^{i\alpha }+{e}^{-i\alpha }}\text{\hspace{0.17em}}.$

### Tall Array Support

This function fully supports tall arrays. For more information, see Tall Arrays.