smsbla

#lang racket/base
(define costfunction
  (lambda (stg freisms kostenprosms x)
    (+ (- stg ( * freisms kostenprosms)) (* kostenprosms x) ) 
  )
)

;tolerance
(define EPS 1e-3)

;f = function, a = start value 1 b = start value 2 n = iterations
(define (bisection f a b n)
  (define m (/ (+ a b) 2))
  (if (> (* (f a) (f b)) 0)
      "No root"
      (if (> (abs (/ (- b a) 2)) EPS)
          (if (< (* (f a) (f m)) 0)
              (bisection f a m (add1 n))
              (bisection f m b (add1 n)))
          m
          )))



(display (bisection (lambda (x) (- (costfunction -50 200 30 x) (costfunction 10 100 3 x) )) -1000 1000 100000) )