[tex]~~~~~~~~~~~~\textit{distance between 2 points} \\\\ (\stackrel{x_1}{-4}~,~\stackrel{y_1}{-1})\qquad (\stackrel{x_2}{-6}~,~\stackrel{y_2}{8})\qquad \qquad d = \sqrt{( x_2- x_1)^2 + ( y_2- y_1)^2} \\\\\\ d=\sqrt{[-6 - (-4)]^2 + [8 - (-1)]^2}\implies d=\sqrt{(-6+4)^2+(8+1)^2} \\\\\\ d=\sqrt{(-2)^2 + 9^2}\implies d=\sqrt{85}[/tex]
