Question

Riko wants to find the distance between the points (−2, −3) and (2, −5). His work is shown.



Riko correct? Explain why or why not

Answer 1

GIVEN :

Riko wants to find the distance between the given two points (-2, -3) and (2, -5). His work is shown .

Also, given that Riko found the distance between the two points is 8 units

TO FIND :

The distance between the given points (-2, -3) and (2, -5)

And Riko correct? Explain why or why not

SOLUTION :

Given that the two points are (-2, -3) and (2, -5)

Let  $(x_1,y_1)$ and $(x_2,y_2)$ be the given points (-2, -3) and (2, -5) respectively.

The formula for the distance between the two points is given below:

$s=\sqrt{(x_2-x_1)^2+(y_2-y_1)^2}$ units

Substitute the points in the formula we get

$s=\sqrt{(2-(-2))^2+(-5-(-3))^2}$

$=\sqrt{(2+2)^2+(-5+3)^2}$

$=\sqrt{4^2+(-2)^2}$

$=\sqrt{16+4}$

$=\sqrt{20}$

$=2\sqrt{5}$

∴ distance $s=2\sqrt{5}$ units.

Comparing with  Riko found the distance between the two points is 8 units we get, Riko's answer is wrong.

∴ the distance between the two points is $2\sqrt{5}$ units.

Riko's answer is incorrect because the distance between the given two points is $2\sqrt{5}$ units.