[tex]\bf ~~~~~~~~~~~~\textit{distance between 2 points} \\\\ (\stackrel{x_1}{3}~,~\stackrel{y_1}{-1})\qquad (\stackrel{x_2}{4}~,~\stackrel{y_2}{6})\qquad \qquad d = \sqrt{( x_2- x_1)^2 + ( y_2- y_1)^2} \\\\\\ d=\sqrt{[4-3]^2+[6-(-1)]^2}\implies d=\sqrt{(4-3)^2+(6+1)^2} \\\\\\ d=\sqrt{50}\implies d\approx 7.07[/tex]