Mathematics
Solving Recurrence Relations via Characteristic Equations
Quick fact
The characteristic equation method transforms a linear recurrence into a polynomial, and solving that polynomial directly reveals the closed-form formula for the sequence. For the Fibonacci sequence, this yields the famous Binet formula, which involves the golden ratio.
Why this is interesting
Have you ever wondered if there's a shortcut to find the 100th Fibonacci number without adding up all the previous ones? The characteristic equation method turns that daunting task into a simple algebraic step.