|
(define (cbrt x)
|
|
(cbrt-iter 1.0 x))
|
|
|
|
(define (cbrt-iter guess x)
|
|
(if (good-enough? guess x)
|
|
guess
|
|
(cbrt-iter (improve guess x) x)))
|
|
|
|
(define (improve guess x)
|
|
(/
|
|
(+ (/ x (* guess guess)) (* 2 guess))
|
|
3))
|
|
|
|
(define (good-enough? guess x)
|
|
(< (abs (- (* guess guess guess) x)) 0.001))
|
|
|