Question

Find the distance between the following pairs of points:
(a, b), (− a, − b)

Answer 1

Distance between the points is given by
$\sqrt{{(x_1-x_2)}^2+{(y_1-y_2)}^2}$
Therfore distance between (a, b) and (− a, − b) is given by
$l=\sqrt{{(a-(-a))}^2+{(b-(-b))}^2}$
$=\sqrt{{\left(2a\right)}^2+{\left(2b\right)}^2}$
$=\sqrt{4a^2+4b^2}=2\sqrt{a^2+b^2}$