Coordinate Graphs, Lines & Slope

quadrant

The two axes cut the coordinate plane into four corner regions, like slicing a window into four panes. Each pane is a quadrant, and which one a point lands in tells you the signs of its coordinates at a glance.

They are numbered I, II, III, IV starting at the top-right and going counterclockwise. Quadrant I has both coordinates positive (+, +); Quadrant II is (−, +); Quadrant III is (−, −); Quadrant IV is (+, −).

Points that sit exactly on an axis belong to no quadrant, because one of their coordinates is zero — they are on the boundary, not inside any pane.

(-3, 5) is in Quadrant II (x negative, y positive); (2, -6) is in Quadrant IV (x positive, y negative).

Signs of (x, y) pin down the quadrant.