Question

What is the distance between points (-42, 63) and (-39, 67)?

Answer 1

Distance = Square Root ((X2 - X1)^2 + (Y2 - T1)^2)
Distance = Square Root ((-39 --42)^2 + (67 - 63)^2)
Distance = Square Root ((3^2 + 4^2))Distance = Square Root (25)Distance = 5
Source:http://www.1728.org/distance.htm

Answer 2

Use the formula:

$A(x_A;\ y_A);\ B(x_B;\ y_B)\\\\|AB|=\sqrt{(x_B-x_A)^2+(y_B-y_A)^2}$

We have:

$A(-42;\ 63);\ B(-39;\ 67)$

substitute:

$|AB|=\sqrt{(-39-(-42))^2+(67-63)^2}=\sqrt{3^2+4^2}\\\\=\sqrt{9+16}=\sqrt{25}=5$