Distance Between Two Points (Leaving Cert Mathematics): Flashcards

$\sqrt{(x_2 - x_1)^2 + (y_2 - y_1)^2}$

Pythagorean theorem

Same distance from both points

Identify coordinates as $(x_1, y_1)$ and $(x_2, y_2)$

Find differences $(x_2 - x_1)$ and $(y_2 - y_1)$

Square the differences

Add the squares

Take the square root

9, not -9

Surd form (e.g., $\sqrt{58}$)

Always positive

Show two sides have equal length