Final answer:
The domain of the quadratic function y = -4x² - x - 3 is all real numbers, as there are no restrictions on the x-values.
Step-by-step explanation:
The domain of a quadratic function represents all the possible x-values for which the function is defined. For any quadratic function in the form of y = ax² + bx + c, the domain is always all real numbers, as there are no restrictions on the x-values that can be plugged into the function. Hence, for the quadratic function y = -4x² - x - 3, the domain is all real numbers.