1. The number 1.4142 is an approximation of the square root of 2, written as $\sqrt{2}$. 2. The exact value of $\sqrt{2}$ is an irrational number, meaning it cannot be expressed exactly as a simple fraction and its decimal form goes on forever without repeating. 3. The value 1.4142 is a rounded decimal approximation commonly used for practical calculations. 4. For example, $\sqrt{2} \approx 1.4142$ is often used in geometry, especially when dealing with the diagonal of a square with side length 1. 5. This approximation helps simplify calculations while maintaining reasonable accuracy.