Final answer:
To find the critical numbers of a function, we need to find the values of x where the derivative of the function is equal to zero or undefined. The critical number of the function f(x) = 7x² + x - 3 is -1/14.
Step-by-step explanation:
To find the critical numbers of the function f(x) = 7x² + x - 3, we need to find the values of x that make the derivative of the function equal to zero. The derivative of f(x) is f'(x) = 14x + 1. Setting this equal to zero, we get 14x + 1 = 0. Solving for x, we find x = -1/14. Therefore, the critical number of the function is -1/14.