Confusing Calculus question?

Given A(-4, -3) and B(6,1), find a formula which expresses the fact that P(x,y) is on the perpendicular bisector of AB.

i dont really understand the question. if u can solve please explain.
thank you in advancee!!

?2012-09-04T08:43:47Z

Favorite Answer

eqn of line between A and B is of the form y = mx + c

where m = (1 - (-3))/(6 - (-4)) = 4/10 = 2/5

Therefore perpedicular to this line will have gradient -1/(2/5) = -5/2

General formula of perpendicular is y = -(5/2)x + c

Because the perpendicular we want is a bisector, ie it cuts the line from A to B in the middle.

ie it cuts at (-4 + (10/2), -3 + (4/2)) = (1, -1)

ie -1 = -(5/2)*1 + c
c = 3/2

equation of perpendicular bisector is y = -(5/2)x + (3/2)