a)
[tex]\begin{gathered} g_{_1\text{ }}=3^{1-1^{}\text{ }}=3^0=1\text{ } \\ g_{2\text{ }}=3^{2-1\text{ }}=3^1\text{ = 3} \\ g_3=3^{3-1}=3^2\text{ = 9} \\ g_4=3^{4-1}=3^3\text{ = 27} \\ g_5=3^{5-1\text{ }}=3^4\text{ = 81} \end{gathered}[/tex]first five terms = 1, 3, 9, 27, 81
b)
[tex]g_{8_{\text{ }}}=3^{8-1}=3^7\text{ = 2187}[/tex]