Graph Basics

The Y Axis Is Vertical, The X Axis Is Horizontal

But you knew that right?

There are 4 Quadrants On A Graph

graph quadrants

  • In quadrant 1, x and y are positive
  • In quadrant 2, x is negative and y is positive
  • In quadrant 3, x and y are negative
  • In quadrant 4, x is positive, y is negative

Coordinates are given in the format (x,y).

Finding The Midpoint Of A Line

This is easy (and really common in exams)…just find the average of the x and y coordinates.

Example: T has coordinates (5,4). U has coordinates (1,-2). Find the midpoint of line TU.

Average x coordinates: (5+1)/2 = 3
Average y coordinates: (4 +(-2))/2 = 1

So the midpoint is (3,1).

Z Coordinates3d graphsThese just add another direction to the graph and make it 3D. The only difference is you now get three coordinates (x, y, z).

If you need to find the midpoint you just average all three coordinates.