CASIN(3) Library Functions Manual CASIN(3)

casincomplex inverse sine function
catan
complex inverse tangent function

#include <complex.h>

double complex
casin(double complex z);

long double complex
casinl(long double complex z);

float complex
casinf(float complex z);

double complex
catan(double complex z);

long double complex
catanl(long double complex z);

float complex
catanf(float complex z);

(z) computes the inverse sine of the complex floating-point number z, with branch cuts outside the interval [-1, 1] on the real axis.

(z) computes the inverse tangent of the complex floating-point number z, with branch cuts outside the interval [-i, i] on the imaginary axis.

Both functions return values in a strip of the complex plane with unbounded imaginary part, and real part in the interval [-Pi/2, Pi/2].

casin and catan are defined in terms of the complex inverse hyperbolic functions as follows:

casin(z) = -i * casinh(i*z),
catan(z) = -i * catanh(i*z).

casinh(3) catanh(3) complex(3)

The casin() and catan() functions conform to ISO/IEC 9899:2011.

December 11, 2006 BSD 4