(define myF1 (lambda (x) (exp x)))

(define myF2 (lambda (x) (exp (* 2 x))))

(define dx 0.000001)

(define deriv
  (lambda (f)
    (lambda (x)
      (/ (- (f (+ x dx))
	    (f x))
	 dx))))

(define nth-deriv
  (lambda (f n)
    (if (= n 0)
	f
	(deriv (nth-deriv f (-1+ n))))))

((nth-deriv myF1 1) 1)

((nth-deriv myF2 1) 1)

(let
    ((f (myF2 2))
     (fd (* 2 (myF2 2)))
     (f~ ((nth-deriv myF2 1) 2)))
  (/ (- f~ fd)
     fd))