Find the sum to n terms of the series
1+5+14+30+55......plz solve fast I will give brain mark plz plz
sandeep187350:
no
nth term is infinity
it isn't Ap
nd not gp
Answers
Answered by
0
...................idk
ur wrong question
it's only fake answer
sry answer*
if you don't mind it's not Ap nd not Gp
what r u saying?
r u urself clear with dat
ya
i noticed
Answered by
1
Answer:
Step-by-step explanation:
- Firstly We will deduce the Tⁿ of this series
So, Let S= 1+5+14+30+55...
(shifting 1) S= 1+5+14+25....
Subtracting these equations
0=1+4+9+16+25...n²-tⁿ
tⁿ=1+4+9+16+25...n²
tⁿ=n(n+1)(2n+1)/6 (therefore it's tⁿ)
2. Simplifying tⁿ a bit
tⁿ=n³/3 + n²/2 + n
Now apply summation as you do.(now it's easy, if any problem arises then ask me. )
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