When X is between -3 and -1, X^2 will be between 1 and 9. For example, if X = -2, X^2 = 4. If X approaches -1 or -3, X^2 approaches 1 or 9 respectively. When Y is between -1 and 1, Y^2 will be between 0 and 1. For example, if Y = 0.5, Y^2 = 0.25. If Y approaches -1 or 1, Y^2 approaches 1. If Y approaches 0, Y^2 approaches 0. Therefore, X^2 - Y^2 will be between 0 (when X^2 is close to 1 and Y^2 is close to 1) and 9 (when X^2 is close to 9 and Y^2 is close to 0).