ID	edc1e044-a8c9-449b-99b0-e6399944a572
DEERTOPIAVISIBILITY	public

Tangent line

In mathematics, geometry, and calculus, the tangent line ...

Inbox

Definition

Sometimes defined as $m_{tan} = \lim_{x \to a} \frac{f x - f a}{x - a},$ but more often defined as $m_{tan} = \lim_{h \to 0} \frac{f (x + h) - f x}{h},$ coinciding with the definition of the derivative.

Equation of the tangent line at a point

The equation of the tangent line at a point $(a, f a)$ is $y = (f^{'} a) (x - a) + f a .$