general term 1,2,4,7,11
回答 (3)
2007-01-12 3:10 am
✔ 最佳答案
1st term: 1=12nd term: 2=1+1
3rd term: 4=1+1+2
4th term: 7=1+1+2+3
5th term: 11=1+1+2+3+4
......
∴nth term= 1+[1+2+3+...+(n-1)]
=1+n(n-1)/2
參考: me
2007-01-12 4:27 am
1st term: 1=1
2nd term: 2=1+1
3rd term: 4=1+1+2
4th term: 7=1+1+2+3
5th term: 11=1+1+2+3+4
......
∴nth term= 1+[1+2+3+...+(n-1)]
=1+n(n-1)/2
2nd term: 2=1+1
3rd term: 4=1+1+2
4th term: 7=1+1+2+3
5th term: 11=1+1+2+3+4
......
∴nth term= 1+[1+2+3+...+(n-1)]
=1+n(n-1)/2
2007-01-12 3:15 am
value of nth term=1+[(n-1)(n)/2]
1st term=[1+(1-1)1/2]=1
2nd term=[1+(2-1)2/2]=2
：
：
：
nth term=1+[(n-1)n/2]
至於why,咪就係睇下每個term之間的diff.
1st term=[1+(1-1)1/2]=1
2nd term=[1+(2-1)2/2]=2
：
：
：
nth term=1+[(n-1)n/2]
至於why,咪就係睇下每個term之間的diff.
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