go/src/math/big/sqrt.go

var threeOnce …

func three() *Float { … }

// Sqrt sets z to the rounded square root of x, and returns it.
//
// If z's precision is 0, it is changed to x's precision before the
// operation. Rounding is performed according to z's precision and
// rounding mode, but z's accuracy is not computed. Specifically, the
// result of z.Acc() is undefined.
//
// The function panics if z < 0. The value of z is undefined in that
// case.
func (z *Float) Sqrt(x *Float) *Float { … }

// Compute √x (to z.prec precision) by solving
//
//	1/t² - x = 0
//
// for t (using Newton's method), and then inverting.
func (z *Float) sqrtInverse(x *Float) { … }

// newFloat returns a new *Float with space for twice the given
// precision.
func newFloat(prec2 uint32) *Float { … }