To answer this question, we need to remember the power of i
[tex]\begin{gathered} i^1=i \\ i^2=-1 \\ i^3=-i \\ i^4=1 \end{gathered}[/tex]The expression i^80 can be re written as (i^4)^20
[tex](i^4)^{20}=(1)^{20}=1[/tex]It means, the number i^80 is equivalent to 1.
