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NAMEacos, acosf, acosl - arc cosine function
DESCRIPTIONThe fBacos()fP function calculates the arc cosine of fIxfP; that is the value whose cosine is fIxfP. If fIxfP falls outside the range -1 to 1, fBacos()fP fails and fIerrnofP is set.
RETURN VALUEThe fBacos()fP function returns the arc cosine in radians and the value is mathematically defined to be between 0 and PI (inclusive).
CONFORMING TOSVID 3, POSIX, BSD 4.3, ISO 9899. The float and long double variants are C99 requirements.
SEE ALSOasin(3), atan(3), atan2(3), cos(3), sin(3), tan(3)