| MATLAB Functions | Help Desk |
cos, cosh
Cosine and hyperbolic cosine
Y = cos(X) Y = cosh(X)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.
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 
.
acos, acosh Inverse cosine and inverse hyperbolic cosine