Approximate e^x

compute-ex.rkt

#lang racket

;; Compute e^x with an approximation
;; 1 + x + x^2/2! + x^3/3! + ... up to ten terms
;; No Defines were hurt in the making of this program
(for-each
 (compose
  displayln
  (λ (s) (apply (λ (a b) (string-append a "." (substring b 0 (if (< (string-length b) 4) (string-length b) 4)))) (string-split s ".")))
  number->string
  exact->inexact
  (λ (x) (+ 1 x (foldl + 0 (map (λ (p) (/ (expt x p) (foldl * 1 (cdr (range (add1 p)))))) (cdr (cdr (range 10))))))))
 (for/list ([x (in-range (read))]) (read)))