The Enigmatic X: A Journey Through the Unknown

Have you ever pondered over the无处不在 letter X? It signs our letters, rates our movies, and even defines generations. But why does this peculiar character hold such a significant place in our lives? How did X, the fourth least common letter in the English language, become a universal symbol of the unknown? Let's embark on a voyage through history and mathematics to uncover the secrets behind the mysterious X.