Question

is 9999 in the sequence n²+2n?​

Answer 1

Answer:

No

Step-by-step explanation:

To find out, all we need to do is plug in 9999 into the sequence.

$9999 = n^2 + 2n$

By completing the square, we get $(n+1)^2 = 1001$. 1001 is not a perfect square, which means that 9999 is not in the sequence.

hope this helped! :)