To simplify $i^4$:

1. Recall that $i$ is the imaginary unit, defined as $i = \sqrt{-1}$.
2. Powers of $i$ cycle in a specific pattern:
   • $i^1 = i$
   • $i^2 = -1$
   • $i^3 = -i$
   • $i^4 = 1$

So, $i^4 = 1$.

Answer: $i^4 = 1$

Would you like further details or have any questions?

Here are some related questions for further exploration:

1. What is the value of $i^5$?
2. How do higher powers of $i$ continue the pattern?
3. What are the applications of imaginary numbers in mathematics?
4. How can complex numbers be represented on a plane?
5. How does one simplify $i^{10}$?

Tip: When dealing with powers of $i$, remember the four-term cycle: $i, -1, -i, 1$.