MATLAB Function Reference

sec

Secant

Syntax

• Y = sec(X)
  

Description

The sec function operates element-wise on arrays. The function's 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.

Examples

Graph the secant over the domains 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
  
  
  

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 .

Definition

The secant can be defined as

Algorithm

sec uses FDLIBM, which was developed at SunSoft, a Sun Microsystems, Inc. business, by Kwok C. Ng, and others. For information about FDLIBM, see http://www.netlib.org.

See Also

asec, asech, eps, pi, sech

script

sech