Secant and hyperbolic secant
Syntax
Y = sec(X)
Y = sech(X)
Description
The sec and sech commands operate element-wise on arrays. The functions' domains and ranges include complex values. All angles are in radians.
Y = sec(X)
returns an array the same size as X containing the secant of the elements of X.
Y = sech(X)
returns an array the same size as X containing the hyperbolic secant of the elements of X.
Examples
Graph the secant over the domains 
and 
and the hyperbolic secant over the domain 
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))
x = -2*pi:0.01:2*pi; plot(x,sech(x))
The expression sec(pi/2) does not evaluate as infinite but as the reciprocal of the floating-point accuracy eps, because pi is a floating-point approximation to the exact value of 
.
Algorithm
See Also
asec, asech Inverse secant and inverse hyperbolic secant
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