Using the following property
[tex]a^{bc}=(a^b)^c[/tex]
We can rewrite our expression as
[tex]i^{86}=i^{2\times43}=(i^2)^{43}[/tex]
i is the imaginary number, also know as the square root of - 1. When squared, the imaginary number is equal to - 1.
[tex](i^2)^{43}=(-1)^{43}[/tex]
