~急~數列~20點~

1. An = 4n
So, the next two terms are n=5 and n=6
i.e. 20 and 24

2. An = 8-n
So, the next two terms are n=5 and n=6
i.e. 3 and 2

3. An = 3 to the square (n-1)
So, the next two terms are n=5 and n=6
i.e. 81 and 243

4. An = n to the square n / (-n) to the square n
So, the next two term is n=5 and n=6
i.e. -1 and 1

5. n=1 , An = 7

6. n=1 , An = 1/2

7. n=1 , An = -1

Similar to 5. to 7.

8. First three terms are 5, 6 and 7

9. First three terms are 1/3, 2/3 and 1

10. First three terms are 17, 14, 11

write down the next 2 terms in each of the folloeing sequences.
1. 4,8,12,16...
4*1=4;
4*2=8;
4*3=12;
4*4=16;
4*5=20;
4*.....=4的倍數。

2. 7,6,5,4...
7-1=6
6-1=5
5-1=4
4-1=3
..-1=最後數值減1

3. 1,3,9,27...
1*3=3
3*3=9
9*3=27
27*3=81
...*3=最後數值*3

4. -1,1,-1,1...
-1,1
-1,1
-1,1
.....循環不止

in each of the following,find the first termof the sequences for each An is the general term
5. An=7n
An=7n
A=7n/n
A=7

6. An=1/2n
An=1/2n
A=1/2n/n
A=1/2

7. An=4n-5
An=4n-5
A=(4n-5)/n
A=4-5/n

in each of the following,find the first 3 terms of the sequences for which Anis the genral term
8. An=n+4
An=n+4
A=(n+4)/n
A=1+4/n

9. An=n/3
An=n/3
A=(n/3/)n
A=1/3

10. An=20-3n
An=20-3n
A=(20-3n)/n
A=20/n-3