Question

Any help? I'm stuck. Find the next three terms in the geometric sequence and write the explicit function used to find the "nth" term. -1, 1, -1, 1, ...

Answer 1

the common ratio, r = 1 / -1 = -1

First term, a = -1

$\begin{gathered} U_n=ar^{n-1} \\ \Rightarrow U_n=(-1)(-1)^{n-1}=(-1)^{n-1+1} \\ \Rightarrow U_n=(-1)^n \end{gathered}$$undefined$