(define (make-center-width c w) (make-interval (- c w) (+ c w))) (define (center i) (/ (+ (lower-bound i) (upper-bound i)) 2)) (define (width i) (/ (- (upper-bound i) (lower-bound i)) 2)) (define (make-center-percent c p) (make-interval c …

(define (div-interval x y) (let *1 (upx (upper-bound x)) (lowy (lower-bound y)) (upy (upper-bound y))) (cond lowx 0) ;;xは正 (cond ((> lowy 0) ;;yは正 (make-interval ( lowx lowy) ( upx upy))) ((< upy 0) ;;yは負 (make-interval ( upx upy) ( …

;; y が0をまたがる区間の時はエラーを返す (define (div-interval x y) (if (> 0 (* (lower-bound y) (upper-bound y))) (error "error") (mul-interval x (make-interval (/ (upper-bound y)) (/ (lower-bound y))))))