If the points are: (4, 3) and (6, 1) then the slope works out as -1
After white moves his king's bishop to c4 on move 3, black takes white's pawn at e4 with his knight from f6.
Many beginners sometimes fall for the scholar's mate (or four-move checkmate), which is 1. e4 e5 2. Bc4 Nc6 3. Qf3 g6?? 4. Qxf7#. The quickest way to win the game (although highly improbable, as black would have to make uncomfortable moves and allow himself to be mated) is 1. e4 f6? 2. d4 g5?? 3. Qh5#
Points: )1, 1) and (3, 3) Slope: 1
A slope of -3 is steeper.
If you mean points of (1, 5) and (-1, -1) then the slope works out as 3
The slope of two lines are perpendicular only if their slopes multiplied together equal -1 (m1*m2 = -1). So if a line has a slope of -3 then a line perpendicular to this one has a slope of -1/-3 or 1/3.
Points: (1, -3) and (2, -5) Slope: -2
If you mean points of (3, 3) and (-3, -1) then the slope works out as 2/3
Slope = (1 - 4)/(3 - 1) = -3/2 = -1.5
Points: (-2, 3) and (1, 1) Slope: -2/3
Points: (-2, 3) and (1, 1) Slope: -2/3
Points: (-3, -1) and (3, -2) Slope: -1/6