Differentiation

Abstract

If y = f(x) then

$$\frac{{dy}}{{dx}} = f'(x) = \mathop {\lim }\limits_{\delta x \to 0} \frac{{f(x + \delta z) - f(x)}}{{\delta x}}$$

or

$$f'(a) = \mathop {\lim }\limits_{b \to a} \frac{{f(a) - f(b)}}{{a - b}}$$