thanks bhaiya.
2 : 14+24+34+44+.......
11 Answers
Lokesh Verma
·2010-04-30 01:23:24
2nd one the first proof is quite boring...
It goes like this:
15-05 = 14
25-15 = 24+23+22+2+1
35-25 = 34+2.33+2232+....
....
....
...
Then add..
student
·2010-04-30 01:45:57
second one same as bhaiya
Σ(n5-(n-1)5)+10Σn3-10Σn2+5Σn-15=Σn4
Σn4=(n5)+10Σn3-10Σn2+5Σn-15
ut10
·2010-04-30 08:00:49
thanks bhaiya gr8
getting Tn= 2n * (n2+5n+6)/2
by multiplying and then doing summation getting right solution.