#| BEGIN (Введите свое решение) |#
(define (square x) (* x x))

(define (sqrt-iter guess x)
  (if
   (good-enough? guess x) guess
   (sqrt-iter (improve guess x) x)
  )
)

(define (improve guess x)
  (average guess (/ x guess))
)

(define (average a b) (/ (+ a b) 2))

(define (good-enough? guess x)
   (< (abs (- (square guess) x))
      0.0001)
)

(define (square-root x) (sqrt-iter 1.0 x))
#| END |#