Question

Find the distance between the following pair of point in the coordinate plane.

(1 , 3) and (3 , 9)

Answer 1

A = (1 , 3) , B = (3 , 9)

AB = `sqrt (("x"_2 - "x"_1)^2 + ("y"_2 - "y"_1)^2)`

`= sqrt ((3 - 1)^2 + (9 - 3)^2)`

`= sqrt (4 + 36)`

`= sqrt 40` units = 2`sqrt 10` units.