You just have to know some basic rules for lines & points in space
-Gradient between 2points = difference in y/difference in x
e.g A(3,2) and B(4,7)
grad(m1) = 7-2/4-3
= 5/1
= 5
-Product of two gradients m1 & m2 = -1
- Parallel lines have same gradient
- On y-axis, x =0 and on x-axis y= 0
- Midpoint = (x1+x2)/2,
(y1+y2)/2. E.g A(3,4) midpoint = (3+4)/2 = 3.5
-Magnitude(distance) between two points is given by
square root?(x1-x2)^2+(y1-y2)^2
^2 = power two
thanks