Question

Find the first 3 terms and the 20th term of the sequence that has the given n th term.
an = (−1)n (n − 8)2

Answer 1

Looks like this?
\[a_n=(-1)^n(n-8)^2\]

Answer 2

yes

Answer 3

?

Answer 4

a_1 =(-1)^1(1-8)^2 =(-1)(-7)^2 = -49
a_2 =(-1)^2(2-8)^2 =(+1)(-6)^2 =36
a_3 =(-1)^3(3-8)^2 =(-1)(-5)^2 = -25

a_20 =(-1)^20(20-8)^2 =(+1)(12)^2 = 144