What is the distance between #(4, 2) # and # (-5, -2) #?

1 Answer
May 26, 2016

The distance is approximately 9.84.

Explanation:

If you have two points with coordinates #(x_1, y_1)# and #(x_2, y_2)# the distance is given by the Pitagora's theorem as:

#d=sqrt((x_1-x_2)^2+(y_1-y_2)^2)#.
For you this mean
#d=sqrt((4+5)^2+(2+2)^2)=sqrt(9^2+4^2)=sqrt(81+16)=sqrt(97)\approx 9.84#.

Be careful when you apply this formula that you have to use the correct signs. For example I have that the #x# coordinate of the second point is #x_2=-5#. In the formula I have #x_1-x_2# that is #x_1 - (-5)# and the double minus results in a +. This is why you see it with a plus sign.