racket kurwa

#lang racket
 (require plot)
(define(abs n)
  (if
   (> n 0)
   n
   (* n -1)))


(define(silnia n)
(if (= n 0)
    1
(* n (silnia ( - n 1)))))


(define (parzyste lst)
  (if
   (null? lst)
   '()
   (if (= (modulo(car lst) 2) 0)
       (cons (car lst)(parzyste (cdr lst)))
             (parzyste(cdr lst)
             )
       )
   )
  )

(define (MYmember? x lst)
(if (null? lst)
    #f
    (if (= (car lst) x)
        ;;then
        #t
        ;;else
        (MYmember? x (cdr lst))
        );;cdr to tail ;;car to head
    )
  )
(define (MYappend lst lst2)
(if (null? lst)
    lst2
    (cons (car lst) (MYappend(cdr lst) lst2))
    ))

;;

(define (nazwa_funkcji f x)
  (/ (- (f x) (f (- x 0.0001)))  0.0001 ))


(define (deriv f) (lambda (x)
  (/ (- (f x) (f (- x 0.0001)))  0.0001 )))


;;(plot (function (deriv cos) -3 30))

(define (qsort a)
  (if (empty? a)
    a
    (let ([p (car a)])         ;;cdr to tail ;;car to head
      (let ([tail (cdr a)])
        (let ([lsr (filter (lambda (x) (< x p)) tail)]);pivot
          (let ([grt (filter (lambda (x) (>= x p)) tail)]);pivot
            (append (qsort lsr) (list p) (qsort grt))))))))

(define (wieksze n lst)
    (if (null? lst)
        '()
        (if (> (car lst) n)
            (cons (car lst) (wieksze n (cdr lst)))
            (wieksze n (cdr lst))
        );!if
   );!if
);!define
(define (mniejsze n lst)
    (if (null? lst)
        '()
        (if (<= (car lst) n)
            (cons (car lst) (wieksze n (cdr lst)))
            (wieksze n (cdr lst))
        );!if
   );!if
);!define