sqrt

(define (square x) (* x x))

(define (abs x)
	(if (< x 0)
		(- x)
		x
	)
)

(define (average x y)
	(/ (+ x y) 2)
)

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

(define (good-enough? guess x)
	(< (abs (/ (- (square guess) x) x))
		0.00001
	)
)

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

(define (sqrt x)
	(sqrt-iter 1.0 x)
)

(display (sqrt 3))