To simplify \(i^{173}\), we need to use the properties of the imaginary unit \(i\), where \(i\) is defined as the square root of -1. The powers of \(i\) cycle every four: \(i, i^2, i^3, i^4\). Specifically, \(i^1 = i\), \(i^2 = -1\), \(i^3 = -i\), and \(i^4 = 1\). We can use this cyclical pattern to simplify \(i^{173}\) by finding the remainder when 173 is divided by 4.
The imaginary unit \(i\) is defined as \(i = \sqrt{-1}\). The powers of \(i\) follow a cyclic pattern:
\[
\begin{align_}
i^1 &= i, \\
i^2 &= -1, \\
i^3 &= -i, \\
i^4 &= 1.
\end{align_}
\]
This cycle repeats every four powers.
To simplify \(i^{173}\), we need to find the remainder when 173 is divided by 4, because the powers of \(i\) repeat every 4 steps.
\[
173 \div 4 = 43 \text{ remainder } 1
\]
So, \(173 \equiv 1 \pmod{4}\).
Since \(173 \equiv 1 \pmod{4}\), we have:
\[
i^{173} = i^1 = i
\]