|MATLAB Function Reference|
cos function operates element-wise on arrays. The function's domains and ranges include complex values. All angles are in radians.
Y = cos(X)
returns the circular cosine for each element of
Graph the cosine function over the domain .
cos(pi/2) is not exactly zero but a value the size of the floating-point accuracy,
pi is only a floating-point approximation to the exact value of .
The cosine can be defined as
cos 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.