Ok, so to so to find gradient with two coordinates you can use this formulae.. m=y2-y1 over x2-x1. Example A=(4,3) and Q(8,5) 4 would be x1, 3 would be y1 , 8 would be x2 and 5 would be y2 put them in the formulae and work it out. its pretty easy after you put them in :)