(define (f) (/ (+ 1 (sqrt 5)) 2))

(define (golden func a b e)
  (let* ((x1 (- b (/(- b a) (f))))
         (x2 (+ a (/(- b a) (f)))))
    (if (< (abs (- a b)) e)
        (* 0.5 (+ a b))
        (if (>= (func x1) (func x2))
            (golden func x1 b e)
            (golden func a x2 e)))))