Derivative
From specialfunctionswiki
Let $X$ be a subset of real numbers, $x_0 \in X$, and let $f \colon X \rightarrow \mathbb{R}$ be a function. We say that $f$ is differentiable at $x_0$ if the limit $$f'(x_0)=\displaystyle\lim_{h \rightarrow 0} \dfrac{f(x_0+h)-f(x_0)}{h}$$ exists.
Properties
Derivative is a linear operator
Relationship between q-derivative and derivative
