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calc/help/avercos
Landon Curt Noll fdbf53d7e8 add vercos(), avercos(), covercos(), acovercos()
Improved trig help files.

Added new vercos(x, [,eps]) for versed cosine and covercos(x, [,eps])
for inverse versed cosine.

Added new avercos(x, [,eps]) for inverse versed cosine and acovercos(x, [,eps])
for inverse coversed cosine.
2023-09-06 00:52:37 -07:00

64 lines
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NAME
avercos - inverse versed trigonometric cosine
SYNOPSIS
avercos(x [,eps])
TYPES
x number (real or complex)
eps 0 < real < 1, defaults to epsilon()
return real
DESCRIPTION
Returns the inverse versed trigonometric cosine of x to a multiple of eps with error less in
absolute value than .75 * eps.
This function is sometimes called averc, or arcvercos, is equivalent to:
avercos(x) = acos(x - 1)
EXAMPLE
; print avercos(.5, 1e-5), avercos(.5, 1e-10), avercos(.5, 1e-15), avercos(.5, 1e-20)
2.0944 2.0943951024 2.094395102393195 2.09439510239319549231
; print avercos(2), avercos(-5), avercos(2 + 3i)
0 3.14159265358979323846-2.47788873028847500481i 1.26319267726418536931-1.86416154415788242834i
LIMITS
0 < eps < 1
LINK LIBRARY
NUMBER *qavercos_or_NULL(NUMBER *q, NUMBER *epsilon);
NUMBER *qavercos(NUMBER *q, NUMBER *epsilon);
COMPLEX *c_avercos(COMPLEX *c, NUMBER *epsilon);
SEE ALSO
sin, cos, tan, cot, sec, csc
asin, acos, atan, acot, asec, acsc
versin, coversin, vercos, avercos
aversin, acoversin, covercos, acovercos
epsilon
## Copyright (C) 2023 Landon Curt Noll
##
## Calc is open software; you can redistribute it and/or modify it under
## the terms of the version 2.1 of the GNU Lesser General Public License
## as published by the Free Software Foundation.
##
## Calc is distributed in the hope that it will be useful, but WITHOUT
## ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
## or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General
## Public License for more details.
##
## A copy of version 2.1 of the GNU Lesser General Public License is
## distributed with calc under the filename COPYING-LGPL. You should have
## received a copy with calc; if not, write to Free Software Foundation, Inc.
## 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
##
## Under source code control: 2023/09/05 23:40:24
## File existed as early as: 2023
##
## chongo <was here> /\oo/\ http://www.isthe.com/chongo/
## Share and enjoy! :-) http://www.isthe.com/chongo/tech/comp/calc/