Question

Calcule a distância entre: A(6,8) e B(1,-4)

Answer 1

$D= \sqrt{(x_1-x_2)^2+(y_-y_2)^2} \\ \\ x-1=6\quad y_1=8\qquad x_2=1\quad y_2=-4 \\ \\ \\ D= \sqrt{(6-1)^2+(8-(-4))^2} \\ \\ D= \sqrt{(5)^2+(12)^2} \\ \\ D= \sqrt{25+144} \\ \\ D= \sqrt{169} \\ \\ \boxed{D= 13}$