posted by Lisa .
Find the distance d(P1,P2)between the points P1 and P2.
*all the 1's and 2's are to be lower down.* Please show work
The distance between the X coordinates is 2 minus -5 = 7. The distance between the Y coordinates is 2 minus 1 = 1. Those two distances are the base and height of a right-angled triangle, so to get the hypoteneuse, use Pythagoras: that gives you that the distance is the square root of (7*7 + 1*1) = sqrt(50) = roughly 7.071. I don't know where the calculus comes in, though.