1. COORDINATE GEOMETRY Distance between 2 points Mid-point of 2 points

2. Distance between two points. 518 3 17 A(5,3) B(18,17) 18 – 5 = 13 units 17 – 3 = 14 units AB 2 = 13 2 + 14 2 Using Pythagoras’ Theorem, AB 2 = (18 - 5) 2 + (17 - 3) 2 y x

3. Distance between two points. In general, x1x1 x2x2 y1y1 y2y2 A(x 1,y 1 ) B(x 2,y 2 ) Length = x 2 – x 1 Length = y 2 – y 1 AB 2 = (y 2 -y 1 ) 2 + (x 2 -x 1 ) 2 Hence, the formula for Length of AB or Distance between A and B is y x

4. Find the distance between the points (-1,3) and (2,-6) Simply by using the formula: (-1,3) and (2,-6) (x 1,y 1 ) and (x 2,y 2 ) Since = 9.49 units (3 sig. fig)

5. The mid-point of two points. 518 3 17 A(5,3) B(18,17) Look at it’s horizontal length = 11.5 11.5 Look at it’s vertical length = 10 10 (11.5,10) Mid-point of AB y x

6. The mid-point of two points. x1x1 x2x2 y1y1 A(5,3) B(18,17) Look at it’s horizontal length Look at it’s vertical length Mid-point of AB y x y2y2 Formula for mid-point is