Lines Matching full:acos
894 /* acos(x)
896 * acos(x) = pi/2 - asin(x)
897 * acos(-x) = pi/2 + asin(x)
899 * acos(x) = pi/2 - (x + x*x^2*R(x^2)) (see asin.c)
901 * acos(x) = pi/2 - (pi/2 - 2asin(sqrt((1-x)/2)))
908 * acos(x) = pi - 2asin(sqrt((1-|x|)/2))
917 double acos(double x) {
943 return 0.0; /* acos(1) = 0 */
945 return pi + 2.0 * pio2_lo; /* acos(-1)= pi */
947 return (x - x) / (x - x); /* acos(|x|>1) is NaN */
