Question

A(4,-7) B(-2,1) find AB

Answer 1

$\bf ~~~~~~~~~~~~\textit{distance between 2 points}\\\\A(\stackrel{x_1}{4}~,~\stackrel{y_1}{-7})\qquadB(\stackrel{x_2}{-2}~,~\stackrel{y_2}{1})\qquad \qquadd = \sqrt{( x_2- x_1)^2 + ( y_2- y_1)^2}\\\\\\AB=\sqrt{[-2-4]^2+[1-(-7)]^2}\implies AB=\sqrt{(-2-4)^2+(1+7)^2}\\\\\\AB=\sqrt{(-6)^2+8^2}\implies AB=\sqrt{36+64}\implies AB=\sqrt{100}\implies AB=10$