.\"  '\" te
.\" to invoke 'tbl', 'eqn', 'pic' in the proper order
.\"
.\" @(#)cplxtrig.3 1.9 00/03/29 SMI;
.\"
.TH CPLXTRIG 3CC4 "07 August 1997"
.\"
.SH NAME
cplxtrig \- trigonometric functions in the C++ complex number math library
.SH SYNOPSIS
.LP
.nf
.ft B
#include <complex.h>
.sp .5v
class complex {
public:
	friend complex cos(const complex);
	friend complex sin(const complex);
	friend complex tan(const complex);
.sp .5v
	friend complex cosh(const complex);
	friend complex sinh(const complex);
	friend complex tanh(const complex);
.sp .5v
	friend complex acos(const complex);
	friend complex asin(const complex);
	friend complex atan(const complex);
	... \fI// remainder not shown here\fB
};
.ft R
.fi
.\"
.SH DESCRIPTION
.LP
These functions are versions of the corresponding floating-point
trigonometric math library functions, overloaded for use with complex numbers.
.TP
.B "complex z = cos(x)" 
Returns the complex cosine of complex angle \fBx\fR.
.TP
.B "complex z = sin(x)" 
Returns the complex sine of complex angle \fBx\fR.
.TP
.B "complex z = tan(x)" 
Returns the complex tangent of complex angle \fBx\fR.
.TP
.B "complex z = cosh(x)" 
Returns the complex hyperbolic cosine of complex angle \fBx\fR.
.TP
.B "complex z = sinh(x)" 
Returns the complex hyperbolic sine of complex angle \fBx\fR.
.TP
.B "complex z = tanh(x)" 
Returns the complex hyperbolic tangent of complex angle \fBx\fR.
.TP
.B "complex z = acos(x)" 
Returns the complex angle whose cosine is complex \fBx\fR.
.TP
.B "complex z = asin(x)" 
Returns the complex angle whose sine is complex \fBx\fR.
.TP
.B "complex z = atan(x)" 
Returns the complex angle whose tangent is complex \fBx\fR.
.\"
.ne 4
.SH "SEE ALSO"
.LP
.na
.BR cplx.intro (3CC4),
.BR cartpol (3CC4),
.BR cplxerr (3CC4),
.BR cplxexp (3CC4),
.BR cplxops (3CC4),
.BR intro (2),
.I C++ Library Reference 
Chapter 2, "The Complex Arithmetic Library."
.\" .TZ ????
.ad
.\"
.SH DIAGNOSTICS
.LP
.TP
.BR sinh(x) " and " cosh(x)
If the imaginary part of \fBx\fR would cause overflow,
returns \fB(0,0)\fR.
If the real part is large enough to cause overflow,
returns a value depending on the sine and cosine
of the imaginary part of \fBx\fR:
.TS
.\"allbox;
.\"ccn.
.sp
.nf
x.imag()	x.imag()	returned value
sin>=0	cos>=0	(HUGE_VAL\&, HUGE_VAL)
sin< 0	cos>=0	(HUGE_VAL\&, \-HUGE_VAL)
sin>=0	cos< 0	(\-HUGE_VAL\&, HUGE_VAL)
sin< 0	cos< 0	(\-HUGE_VAL\&, \-HUGE_VAL)
.fi
.sp
.TE
In all cases, \fBerrno\fR is set to \fBERANGE\fR (see \fBintro\fR(2)).
See also \fBcplxerr\fR(3CC4).