Ex 2.46
(define (make-vect x y) (list x y)) (define (xcor-vect v) (car v)) (define (ycor-vect v) (cadr v)) (define (add-vect a b) (make-vect (+ (xcor-vect a) (xcor-vect b)) (+ (ycor-vect a) (ycor-vect b)))) (define (sub-vect a b) (make-vect (- (xcor-vect a) (xcor-vect b)) (- (ycor-vect a) (ycor-vect b)))) (define (scale-vect s v) (make-vect (* s (xcor-vect v)) (* s (ycor-vect v))))