Lesson 2-4 The Coordinate Plane Applied Geometry Lesson 2-4 The Coordinate Plane Objective: Learn to graph ordered pairs on a coordinate plane

Coordinate Plane Origin (0,0) The number plane formed by two perpendicular number lines that intersect at their zero points to form a grid. Origin (0,0)

Quadrants The four regions of the coordinate plane II I III IV

Ordered pair Ordered pair (x, y) Coordinates: an ordered pair of real numbers used to locate a point on a coordinate plane. (3, 5) 3 is the x-coordinate 5 is the y-coordinate

Graph Graph: the point in the coordinate plane. Graphing: locating the point in the coordinate plane

Postulate 2-4 Completeness Property for Points in the Plane Each point in a coordinate plane corresponds to exactly one ordered pair of real numbers. And vice versa.

Example B (-2, 4) C (0, -3) D (-3, -2) Name the coordinates of B, C, and D. B (-2, 4) C (0, -3) D (-3, -2)

Example Go right 2, down –3. A would be in IV quadrant. Graph point A at (2, -3) Describe its location Go right 2, down –3. A would be in IV quadrant.

Theorem If a and b are real numbers, a vertical line contains all points (x,y) such that x = a, and a horizontal line contains all points (x, y) such that y = b.

Graph y = 4 x = -3 x = 2 y = -1 x = 0

Homework Pg. 71 1 – 14 all, 16 – 44 E