2. 2 .. (Deduction) (Induction) 3. 4. 5. 6. 1) 2) 3) 7. 1. 8. 2.
9. 3. 10. 1. 2. 3. 4. 5. 11. 12. 13. () 1. 2. 3. 14. 15. () 1 , 2 ,
3 , 4 , 5 , 6 , 7 , 8 , 9 ,10 ... 5 11 , 12 , 13 , 14 , 15 16. () 1
=1 1+2 = 3 1+2+3 = 61+2+3+4 =10 1+2+3+4+5 =15 1 + 2 + 3 + 4 + ...
+n = n(n+1)/2 17. 1 + 2 + 3 + 4 + ... + n = n(n+1)/21 = 1(1+1)/2
=11+2=2(2+1)/2 =31+2+3 = 3(3+1)/2 =61+2+3+4+5+6= 6(6+1)/2= 211 + 2
+ 3 + 4 + ... + 10= 10(10+1)/2 = 551 + 2 + 3 + 4 + ... + 12 =
12(12+1)/2= 78 18. 2n > n2 n > 4 25 > 52= 32 > 25 26
> 62= 64 > 36 2 7 > 72 = 128 > 49 28 > 82= 256 >
64 19. 1. / 1) __________ 2) __________ 3) __________ 4) __________
5) __________ 20. 4. 1)(1 9) + 2= 11(12 9) + 3 = 111 (123 9) + 4 =
1111 _____________ = _______ 2) 2 = 4-2 2+4 =8-2 2+4+8
=16-22+4+8+16=32-2_________ = ______ 21. 4. 1,089 x 1 =1,0891,089 x
2 =2,1781,089 x 3 =3,2671,089 x 4 = ______1,089 x 5 = 4356
______1,089 x 6 =______1,089 x 7 =______1,089 x 8=______1,089 x 9
=______ 22. " n 2n
