Q1
a) Y is directly below X, so to find distance XY, just get top point minus bottom point (y-values) (XY is a vertical distance)
Before this is all done, tell me what point X and Y are
b) Calculus
Q2
a) U can do this, use what they gave u, the point (-1,2) lies on AB --> what does this mean...?
b) To find 2 unknowns, u need 2 equations. Make another equation with 'a' and 'b' (i.e. a relation between a and b) somehow...
If (-1,2) lies on the line AB, what else can u deduce besides that (-1,2) satisfies eqn AB? (it'll be helpful if you can produce a diagram to inspect)