Returns the hyperbolic cosine of a complex number.
The hyperbolic cosine of a complex number can be expressed by its real and imaginary parts:
IMCOSH(Complex_number)
Complex_number is a complex number whose hyperbolic cosine is to be calculated.
A complex number is a string expression resulting in the form "a+bi" or "a+bj", where a and b are numbers.
If the complex number is actually a real number (b=0), then it can be either a string expression or a number value.
The function always returns a string representing a complex number.
If the result is a complex number with one of its parts (a or b) equal to zero, that part is not displayed.
=IMCOSH("4-3i")
returns -27.0349456030742-3.85115333481178i.
=IMCOSH(2)
returns 3.76219569108363 as a string. The imaginary part is equal to zero, so it is not displayed in the result.
