The Straight Line_1

The Straight Line_1

1. Gradients

2. Distance Formula

3. Midpoint Formula

4. Collinearity

   • 1) Find Gradient of AB
   • 2) Find Gradient of BC or AC
   • 3) If gradients are the same, then A, B, C are collinear

5. Equation of a Straight Line

   • y-b=m(x-a)
   • y=c
   • x=k

6. Medians

   • 1) Sketch ABC and calculate midpoint
   • 2) Calculate the gradient of the line between midpoint and opposite vertex
   • 3) Find the equation using the gradient and the point A or the midpoint

7. Altitudes

   • 1) Sketch ABC and calculate gradient of line perpendicular to altitude
   • 2) calculate perpendicular gradient
   • 3) Find the equation using the gradient and the point A that the altitude passes through

8. Perpendicular Bisectors

   • 1) Calculate the midpoint of the line being bisected
   • 2) Calculate the gradient of the line from step 1. Find the perpendicular gradient
   • 3) Find the equation using the point from step 1 and gradient from step 2