Question

Find the $n^{\text{th}}$ term of sequence 0, 3, 8, ...

• A. $n^2$ - 1
• B. $n^3$ - 1
• C. 2$n^2$ - 2
• D. 2n-1

Answer 1

The correct option is A $n^2$ - 1

$T_1$ = $1^2$ - 1 = 1 - 1 = 0 OR
= (1-1)$\times$(1+1) = 0$\times$2 = 0
$T_2$ = $2^2$ - 1 = 4 - 1 = 3 OR
= (2-1)$\times$(2+1) = 1$\times$3 = 3
$T_3$ = $3^2$ - 1 = 9 - 1 = 8 OR
= (3-1)$\times$(3+1) = 2$\times$4 = 8
thus
$T_n$ = $n^2$ - 1 OR
= (n-1)$\times$(n+1) = $n^2$ + n - n - 1 = $n^2$ - 1