Answer:
n^2 - 2n - 6.
Step-by-step explanation:
The difference between terms is
1 3 5 7 9 11 which is an arithmetic sequence with common difference 2.
The given series is quadratic and the nth term will contain n^2.
n = 1 2 3 4 5
n^2 = 1 4 9 16 25
term = -7 -6 -3 2 9 Subtract these from the n^2 values:
Subtract: 8 10 12 14 16
The last row is an A.S. with nth term 8 + 2(n - 1) = 6 + 2n
So the required nth term = n^2 - (6 + 2n)
= n^2 - 2n - 6.
