(define (calc-e n)
  (accumulate
    +                           ;combiner
    0                           ;null-value
    (lambda (n)
      (/ 1 (factorial n)))      ;term
    0                           ;a
    (lambda (n) (+ n 1))        ;next
    n))                         ;b
(define (calc-sin x n)
  (accumulate
    +                           ;combiner
    0                           ;null-value
    (lambda (n)
      (/ (expt x (+ (* n 2) 1))
         (factorial (+ (* n 2) 1))))    ;term
    0                           ;a
    (lambda (n) (+ n 1))        ;next
    n))                         ;b
;het nadeel van deze aanpak is dat hij minder effici‰nt werkt...