Lines Matching defs:cbrt
21 /* cbrt(x)
28 /* |1/cbrt(x) - p(x)| < 2**-23.5 (~[-7.93e-8, 7.929e-8]). */
37 cbrt(double x)
51 if(hx>=0x7ff00000) return(x+x); /* cbrt(NaN,INF) is itself */
54 * Rough cbrt to 5 bits:
55 * cbrt(2**e*(1+m) ~= 2**(e/3)*(1+(e%3+m)/3)
70 return(x); /* cbrt(0) is itself */
79 * New cbrt to 23 bits:
80 * cbrt(x) = t*cbrt(x/t**3) ~= t*P(t**3/x)
81 * where P(r) is a polynomial of degree 4 that approximates 1/cbrt(r)
83 * has produced t such than |t/cbrt(x) - 1| ~< 1/32, and cubing this
93 * the result is larger in magnitude than cbrt(x) but not much more than
116 __weak_reference(cbrt, cbrtl);