Cho hàm số \(y=f\left(x\right)\) có đạo hàm tại \(x_0\) thì \(\lim\limits_{x\rightarrow x_0}\frac{x_0f\left(x\right)-xf\left(x_0\right)}{x\rightarrow x}\) bằng :
\(x_0f\left(x_0\right)\) \(x_0f\left(x_0\right)-f\left(x_0\right)\) \(x_0f\left(x_0\right)-f'\left(x_0\right)\) \(f\left(x_0\right)-f'\left(x_0\right)\)