NCNU LISP HW7

(define (iterative-improve ok? do)
(define (iim guess)
(if (ok? guess) guess
                    (iim (do guess))
)
)
iim)
(define (square x)
(* x x))
(define (average x y)
    (/ (+ x y) 2))

(define (sqrt x)
   ((iterative-improve (lambda (guess)
                        (< (abs (- (square guess) x)) 0.001))
                       (lambda (guess)
                          (average guess (/ x guess))))
   1.0)
)

(define (fixed-point f guess)
   ((iterative-improve (lambda (guess)
                          (< (abs (- (f guess) guess)) 0.00001))
                       (lambda (guess)
                          (f guess)))
    guess)
)