Question

What is the distance, in radical form, between the points (4,6) and (8,-2)?

Answer 1

$d = \sqrt{(x_{2} - x_{1})^{2} + (y_{2} - y_{1})^{2}} \\d = \sqrt{(8 - 4)^{2} + (-2 - 6)^{2}} \\d = \sqrt{(4)^{2} + (-8)^{2}} \\d = \sqrt{16 + 64} \\d = \sqrt{80} \\d = \sqrt{16 * 5} \\d = \sqrt{16}\sqrt{5} \\d = 4\sqrt{5}$