1. How To Design
Programs

2. •
•
•
•

3. •
•
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•

4. •
• (generative recusion)
• (accumulation)
• (history sensitivity)

5. Scheme
•
•
•
• .

6. 2 , ,
•
• (+ 5 5), (- 5 5), (* 3 4), (/ 8 12)
• (* (+ 2 2) (/ (* (+ 3 5) (/ 30 10)) 2))

7. • = 3.14 * r^2
• (define (area-of-disk r)
(* 3.14 (* r r)))
• (define (area-of-ring outer inner)
(- (area-of-disk outer)
(area-of-disk inner)))
• (area-of-ring 5 3)

8. 2.2.1
• [C]=([F]-32)*5/9
• (define (Fahrenheit->Celsius t)
(* (- t 32) (/ 5 9)))
• convert.ss (teachpack)
• (convert-gui Fahrenheit->Celsius)

9. 2.4
•
- (define (P x)
(+ (x) 10))
•
- (define (f n)
(+ (/ n 3) 2))
- (f 5 8)

10. 2.5
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•
•
•
•

11. 3
+
•
. (Divide And Conquer)

14. •
.
• !!!

15. 3.2
• (define PI 3.14)
• (define PI 3.14159)

16. •
.

17. 4 .
x=y (= x y)
x<y (< x y)
x>y (> x y)

18. (and (= x y) (< y z))
(or (= x y) (< y z))
(not (= x y))
true, false

19. (define (is-5? n)
Is 5 ?
(= n 5))
(define (is-between-5-6? n)
(5, 6)
(and (< 5 n) (< n 6)))
(5, 6) or (define (is-between-5-6-or-over-10? n)
over 10? (or (is-between-5-6? n) (>= n 10)))

21. • .( )
• .