Question

If unity is added to the sum of any number of terms of the A.P. 3, 5, 7, 9,…... the resulting

sum is

(a) ‘a’ perfect cube (b) ‘a’ perfect square (c) ‘a’ number (d) none​

Answer 1

Answer: (b) a perfect square

Step-by-step explanation:

Sum of n terms, Sₙ = n/2[2a+(n-1)d]

=n/2[2x3+(n-1)2]

=n/2(2n+4)

=n/2[2(n+2)]

=n(n+2)

When 1 is added to the sum, Sₙ+1 = n(n+2)+1

=n²+2n+1

=(n+1)², which is a perfect square

Answer 2

Answer:

(B) ---------> A perfect square

I HOPE UR DOUBT GOT COMPLETELY CLEARED...

I HOPE UR DOUBT GOT COMPLETELY CLEARED...PLEASE MARK ME AS BRAINLIEST