Question

The sum of n terms of a sequence is 3n2+4n.find 50 term and nth term

Answer 1

HELLO DEAR,


Given sₙ = 3n2  + 4n

S₁ = 3×1 + 4×1 = 7.

S₂ = 3×4 + 4×2 = 12 + 8 = 20.


First term a₁ = 7 &  Second term a₂ = 20 - 7 = 13


and d = 13 - 7 = 6.

Now ₅₀th term an = 7 + ( 50 - 1) 6

a₅₀ = 7 + 49 x 6

a₅₀ = 7+294 =301

I HOPE ITS HELP YOU DEAR,
THANKS