# sqrt newton way

I was working through a way to get a square-root function to work in scheme.

```
(define (sqrt2 x)
(sqrt-iter 1 x))
(define (sqrt-iter guess x)
(if (good-enough guess x)
guess
(sqrt-iter (make-guess guess x) x)))
(define (make-guess guess x)
(/ (+ (/ x guess) guess) 2))
(define (good-enough guess x)
(< (abs2 (-(* guess guess) x)) 0.001))
(define (abs2 x)
(if (< x 0)
(- 0 x)
x))
```

Running:

```
(sqrt2 100)
```

I got the number 10 followed by the precision: 139008452377144732764939786789661303114218850808529137991604824430036072629766435941001769154109609521811665540548899435521 / 993650612510151824074958925538589300439185013461061345483147770187307778405188218146967823138235109552370030745199319835640898137728

A precision I wonâ€™t forget. COOL!!!