Could the fourth root of $1$ be $i$ (or $-i$)? I could show this by doing:
- $\sqrt[4]{1}$
- $\sqrt{\sqrt{1}}$
- $\sqrt{\pm{1}}$
- $\sqrt{1}$ OR $\sqrt{-1}$
- $\pm1$ OR $\pm i$
- $\{1, -1, i, -i\}$
Would you include the negative square root from step 3 and include $\pm i$? Or would you simply come up with $\pm1$?
Precisely, no. $i$ is a fourth root of $1$, and not the fourth root of $1$.