Question

Find the distance between the points P(1, –3, 4) and Q (– 4, 1, 2).

Answer 1

don't tell me this has to be done mentally o.O

Answer 2

It is to be done mentally. But How ?

Answer 3

\[\huge 3\sqrt 5\]
Using a very attentive mind, I suppose...
distance formula...
\[\huge D = \sqrt{(x_1-x_2)^2+(y_1-y_2)^2+(z_1-z_2)^2}\]

Answer 4

I did it mentally, but using that formula above...