# Derivative by definition

## How do you find slope if you only know 1 point ??? |

## A Specific Example of our dilemna

Imagine that we have some curve, like the red one below, and we know that the point (1,2) is on that curve. The slope of the purple line is the derivative so all that we need to know is the slope of the purple line.But how do we find the slope of a line when we only know 1 point ?

$slope = \frac{\Delta y}{\Delta x} = \frac{2 - \color{red}{?} }{1 - \color{red}{?} } $

Calculator Calculus Homework

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