Question

the sum of series 1+4+9+16+.....to n terms is
a.n^2
b.n(n+1)÷2
c.n(n+1)(2n+1)÷6
d.[n(n+1)÷2]^2​

Answer 1

the series 1, 4, 9, 16, ......n . Theyare not in AP or GP.

Sn = 1+2^2+3^2+....n^2 which is equal to n(n+1)(2n+1)/6

option C is correct.