[SOLVED] CS (define (sqrt x)

(define (sqrt x)
(define (square y)(* y y))

;(define (good-enough? guess)
;(< (abs (- (square guess) x)) 0.001))(define (good-enough? guess)(let ((tolerance 0.001) (difference (abs (- (square guess) x)))) (< difference tolerance)))(define (average x y)(/ (+ x y) 2))(define (improve guess)(average guess (/ x guess)))(define (sqrt-iteration guess)(if (good-enough? guess)guess(sqrt-iteration (improve guess))))(sqrt-iteration 1.0))(let ((a 1)(b (+ 1 1)))(+ a b))(define (letExample c)(let ((a 10)(b 7))(+ a b c)))(letExample 13)(define (letEx2 x)(+ (let ((x 3)) (+ x (* x 10))) x))(letEx2 5)#|(define (letEx3)(let ((x 3)(y (+ x 1))) ;error, x is undefined (* x y)))|#(define (letEx3)(let ((x 3))(let ((y (+ x 1))) (* x y))))(letEx3)(define (letEx3b)(let* ((x 3)(y (+ x 1)))(* x y)))(letEx3b)#|(define (usingDef x)(if (> x 0)
(begin (define y 7)
(+ x y))))|#
;(usingDef 17)

(define (usingLet x)
(if (> x 0)
(let ((y 7))
(+ x y))))
(usingLet 17)