Find the Second Term a_n=21-2n^2

$a_{n} = 21 - 2 n^{2}$

Step 1

Substitute in the value of $n$ to find the $n$ th term.

$a_{2} = 21 - 2 {(2)}^{2}$

Step 2

Simplify each term.

Raise $2$ to the power of $2$ .

$a_{2} = 21 - 2 \cdot 4$

Multiply $- 2$ by $4$ .

$a_{2} = 21 - 8$

Step 3

Subtract $8$ from $21$ .

$a_{2} = 13$