Derivatives · Exercise 65

Use the definition for the derivative at a point $x=a,$ $\underset{x\to a}{\lim }\frac{f\left(x\right)-f\left(a\right)}{x-a},$ to find the derivative of the functions.

$f\left(x\right)=5x^2-x+4$

OpenStax, Precalculus 2e · §12.4 Derivatives · Exercise 65