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.\" Copyright (c) 2011 Jukka Ruohonen <jruohonen@iki.fi>
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.Dd September 13, 2011
.Dt POW 3
.Os
.Sh NAME
.Nm pow ,
.Nm powf
.Nd power functions
.Sh LIBRARY
.Lb libm
.Sh SYNOPSIS
.In math.h
.Ft double
.Fn pow "double x" "double y"
.Ft float
.Fn powf "float x" "float y"
.Sh DESCRIPTION
The
.Fn pow
family of functions returns
.Fa x
raised to the power of
.Fa y .
.Pp
If
.Fa x
is negative and
.Fa y
is not an integer, the global variable
.Va errno
is set to
.Er EDOM ,
and on
.Tn VAX
a reserved operand fault is generated.
A portable application should nevertheless ensure that
.Fa y
is an integer value whenever
.Fa x
is negative.
.Sh RETURN VALUES
.\"
.\" XXX: List also the special return values?
.\"
Upon successful completion, the described functions return
.Fa x^y .
.Sh SEE ALSO
.Xr exp 3 ,
.Xr log 3
.Sh STANDARDS
The described functions conform to
.St -isoC-99 .
.Sh HISTORY
The history of the power functions dates back to
.At v6 .