(define (square-root x) (define (avg a b) (/ (+ a b) 2)) (define (abs a) (if (< a 0) (- x) x)) (define (improve-guess guess) (avg guess (/ x guess))) (define (isgood-guess? guess) ( < (abs (- (square guess) x)) .001)) (define (try guess) (if (isgood-guess? guess) guess (try (improve-guess guess)))) (try 1) )