(define (cube x) (* x (* x x))) (define (square x) (* x x)) (define (my-sqrt3 x) (sqrt3-iter 1.0 x)) (define (sqrt3-iter guess x) (if (good-enough? guess x) guess (sqrt3-iter (improve guess x) x))) (define (good-enough? guess x) (< (abs(- (cube guess) x)) 0.001)) (define (improve y x) (/ (+ (/ x (square y)) (* 2 y)) 3))