IMSL C# Numerical Library

Complex.Cosh Method 

Returns the hyperbolic cosh of a Complex.

public static Complex Cosh(
   Complex z
);

Parameters

z
A Complex object.

Return Value

A newly constructed Complex initialized to the hyperbolic cosine of the argument.

Remarks

If z = x+iy,

\cosh(\bar{z}) = \overline{\cosh(z)} and cosh is even.

\cosh(+0 + i0) returns 1 + i0.

\cosh(+0 + i\infty ) returns \NaN \pm  i0 (where the sign of the imaginary part of the result is unspecified).

\cosh(+\infty + i0) returns +\infty + i0.

\cosh(+\infty + i\infty ) returns +\infty + i\NaN.

\cosh(x + i\infty ) returns \NaN + i\NaN, for finite nonzero x.

\cosh(+\infty + iy) returns +\infty [\cos(y)+i\sin(y)], for finite nonzero y.

\cosh(+0 + i\NaN) returns \NaN \pm  i0 (where the sign of the imaginary part of the result is unspecified).

\cosh(+\infty + i\NaN) returns +\infty + i\NaN.

\cosh(x + i\NaN) returns \NaN + i\NaN, for finite nonzero x.

\cosh(\NaN + i0) returns \NaN \pm  i0 (where the sign of the imaginary part of the result is unspecified).

\cosh(\NaN + iy) returns \NaN + i\NaN, for all nonzero numbers y.

\cosh(\NaN + i\NaN) returns \NaN + i\NaN.

See Also

Complex Class | Imsl.Math Namespace