Question

Find the first five terms of the following sequence, starting with n=1. tn=(−1)n+1(n2−9) Give your answer as a list, separated by commas. For example, if tn=n, you would give your answer as 1,2,3,4,5.

Answer 1

Answer:

-8, 5 , 0 , -7 , 16

Step-by-step explanation:

Given

$t_n = (-1)^{n+1}(n^2 - 9)$

Required

The first five terms

When $n = 1$

$t_1 = (-1)^{1+1}(1^2 - 9)$

$t_1 = (-1)^{2}(1 - 9)$

$t_1 = -8$

When $n =2$

$t_2 = (-1)^{2+1}(2^2 - 9)$

$t_2 = (-1)^3 * (4 - 9)$

$t_2 = 5$

$t_3 = (-1)^{3+1}(3^2 - 9)$

$t_3 = (-1)^{4}(9 - 9)$

$t_3 = 0$

$t_4 = (-1)^{4+1}(4^2 - 9)$

$t_4 = (-1)^5(16 - 9)$

$t_4 = -7$

$t_5 = (-1)^{5+1}(5^2 - 9)$

$t_5 = (-1)^{6}(25 - 9)$

$t_5 = 16$

So, the first five terms are: -8, 5 , 0 , -7 , 16