Line Segment Division (Leaving Cert Mathematics): Flashcards

Internal or external

$x = \frac{mx_2 + nx_1}{m + n}$

$y = \frac{my_2 + ny_1}{m + n}$

$x = \frac{mx_2 - nx_1}{m - n}$

$y = \frac{my_2 - ny_1}{m - n}$

When $m = n$

$x = \frac{x_1 + x_2}{2}$

$y = \frac{y_1 + y_2}{2}$

Internal uses + (both numerator and denominator); external uses - (both)

Finding points in ratios, proportions, midpoints, symmetry