cos, cosh (MATLAB Function Reference)

Cosine and hyperbolic cosine

Syntax

Y = cos(X)
Y = cosh(X)

Description

The cos and cosh functions operate element-wise on arrays. The functions' domains and ranges include complex values. All angles are in radians.

Y = cos(X)

returns the circular cosine for each element of X.

Y = cosh(X)

returns the hyperbolic cosine for each element of X.

Examples

Graph the cosine function over the domain

and the hyperbolic cosine function over the domain

x = -pi:0.01:pi; plot(x,cos(x))
x = -5:0.01:5; plot(x,cosh(x))

The expression cos(pi/2) is not exactly zero but a value the size of the floating-point accuracy, eps, because pi is only a floating-point approximation to the exact value of

Algorithm