You take the derivative of y with respect to x. You are finding the sensitivity to the change in the function with respect to a change in the argument.

Morris Marden, Logarithmic Derivative of an Entire Function, Proceedings of the American Mathematical Society, Vol. 28, No. 2 (May, 1971), pp. 513-518 ...

Learn what a derivative is, its types, uses in finance, and how they work. Discover why derivatives play a crucial role in risk management and investment strategies.

Rajendra Bhatia, John A. Holbrook, Fréchet Derivatives of the Power Function, Indiana University Mathematics Journal, Vol. 49, No. 3 (Fall, 2000), pp. 1155-1173 ...