Equation of a Line (Leaving Cert Mathematics): Flashcards

All points that lie on that particular line

$y - y_1 = m(x - x_1)$

$m = \frac{y_2 - y_1}{x_2 - x_1}$

They have the same slope

Slopes are negative reciprocals of each other

$-\frac{1}{m}$

$ax + by + c = 0$

$y = mx + c$

General form: $ax + by + c = 0$

Calculate the slope using slope formula

One point $(x_1, y_1)$ and slope $m$

All satisfy same relationship between $x$ and $y$