;; bulls-eye? : Number Number -> Boolean
;; determines if (x,y) is in the bull's eye
(define (bulls-eye? x y)
  (<= (dist-to-origin x y) 5))

;; dist-to-origin : Number Number -> Number
;; determines distance from (0,0) to (x,y)
(define (dist-to-origin x y)
  (sqrt (+ (* x x) (* y y))))

;; Examples, test cases for dist-to-origin
(dist-to-origin 0 0) "should be" 0
(dist-to-origin -1 -1) "should be approximately" 1.414
(dist-to-origin 3 4) "should be" 5
(dist-to-origin 5 12) "should be" 13

;; Examples, test cases for bulls-eye?
(bulls-eye? 0 0) "should be" true
(bulls-eye? 0 5) "should be" true
(bulls-eye? 5 0) "should be" true
(bulls-eye? 0 6) "should be" false
(bulls-eye? 7 0) "should be" false
(bulls-eye? -2 10) "should be" false