CEXP(3)
 CEXP(3) FreeBSD Library Functions Manual CEXP(3)

# NAME

cexp, cexpfcomplex exponential functions

# LIBRARY

Math Library (libm, -lm)

# SYNOPSIS

#include < complex.h>

double complex
cexp( double complex z);

float complex
cexpf( float complex z);

# DESCRIPTION

The cexp() and cexpf() functions compute the complex exponential of z, also known as cis( z).

# RETURN VALUES

For real numbers x and y, cexp() behaves according to Euler's formula:

cexp( x + I*y) = ( e** x * cos( y)) + ( I * e** x * sin( y))

Generally speaking, infinities, zeroes and NaNs are handled as would be expected from this identity given the usual rules of floating-point arithmetic. However, care is taken to avoid generating NaNs when they are not deserved. For example, mathematically we expect that cimag( cexp( x + I*0)); = 0 regardless of the value of x, and cexp() preserves this identity even if x is infinity or NaN. Likewise, cexp( -infinity + I*y) = 0 and creal( cexp( infinity + I*y)); = infinity for any y (even though the latter property is only mathematically true for representable y.) If y is not finite, the sign of the result is indeterminate.

complex(3), exp(3), math(3),

# STANDARDS

The cexp() and cexpf() functions conform to ISO/IEC 9899:1999 (“ISO C99”).
 March 6, 2011 FreeBSD