Section 4-1 Plot Points in a Coordinate Plane Objective: Students will plot and identify points on the coordinate grid Standard: Pre-Req knowledge

The ordered pair (0,0) is the coordinates of the origin. A coordinate plane: has a horizontal x-axis and a vertical y-axis that intersect at a point called the origin. In an ordered pair: the first number is the x-coordinate (Move Right or Left) the second number is the y-coordinate.(Move Up or Down) (4, 5) x-coordinate y-coordinate

Coordinate Plane y axis x axis Origin (0,0) Quadrant I (+,+) Quadrant IV (+,-) Quadrant II (-,+) Quadrant III (-,-) The four regions of the coordinate plane are called quadrants The quadrants are labeled I, II, III & IV.

Example 1 Give the coordinates of points A and B A B (2, 3) (5, 6)

Example 2 Plot the points C(-3,0), D(1,-4) and E(-4,-3) on a coordinate plane. C D E Point C is on which axis? Point D is in which quadrant? Point E is in which quadrant? The x-axis Quadrant IV Quadrant III

Example 3 Graph the function y = ½ x + 1 with domain -4, -2, 0, 2 and 4. Identify the range. Step 1 Make input/output table x (domain)y = ½ x + 1y (range) y = ½ (-4) + 1 y = ½ (-2) + 1 y = ½ (0) + 1 y = ½ (2) + 1 y = ½ (4)

Plot a point for each ordered pair (x, y). Step 2Plot the points x y0123

Homework Section 4-1 Pg. 209 – all, , 37, 39