厚土Go学习笔记 | 13. 用循环和函数 实现Sqrt(x)

package main

import (
    "fmt"
    "math"
)

func Sqrt(x float64) float64 {
    var z float64 = 1.0
    for i:= 1; i < 10; i++{
        z = z - (z * z - x)/(2 * z)
        fmt.Println(z)
    }
    return z
}

func main() {
    fmt.Printf("My Sqrt(%d) is %g\n", 2, Sqrt(2))
    fmt.Printf("math.Sqrt(%d) is %g\n", 2, math.Sqrt(2))
}

1.5
1.4166666666666667
1.4142156862745099
1.4142135623746899
1.4142135623730951
1.414213562373095
1.4142135623730951
1.414213562373095
1.4142135623730951
My Sqrt(2) is 1.4142135623730951
math.Sqrt(2) is 1.4142135623730951