Straight Line Graphs

Straight Line Graphs

1. Formula

   • y=mx±c
     • m = gradient
     • c = y intercept

2. Parallel Lines

   • y=2x+1 y=2x-1
   • Parallel lines always have the same gradient

3. Perpendicular Lines

   • y=2x+1 y=(-1/2)x-3
   • The gradient of a perpendicular line is the negative reciprocal of the line to which it is perpendicular

4. Gradient

   • gradient is the difference in y / difference in x
     • can be expressed as ∆Y/∆X

5. Y intercept

   • The y intercept of a line is the point at which that line crosses the y axis