Question

the sum of the first n term of the series √8,√32,√72,√128.........................is----------

Answer 1

series is 2√2,4√2,6√2,8√2....
a=2√2
d=2√2 (common difference)
nth term is =2√2+(n-1)2√2

=2√2(1+n-1)
=n2√2

sum of AP=n/2(a+nth term)

=n/2[2√2+2√2n)]

=n/2*2√2[1+n]

=√2n(1+n)