Rectangular Coordinates & Linear Equations

1. Rectangular Coordinates & Linear Equations

2. Rectangular Coordinates • Parts of a coordinate plane • Y axis • Vertical line • X axis • Horizontal line • Quadrants • The 4 parts that the coordinate plane is divided into

4. Quadrants • The upper right quadrant is the first quadrant and the rest go counterclockwise.

5. Points in Quadrant 1 have positive x and positive y coordinates. • Points in Quadrant 2 have negative x but positive y coordinates. • Points in Quadrant 3 have negative x and negative y coordinates. • Points in Quadrant 4 have positive x but negative y coordinates.

6. X and Y Coordinates • X-Coordinate • Tells how far the point is to the right or left of the y-axis • The first number in the set • Y-Coordinate • Tells how far above or below the x-axis • The second number in the set

7. (x-coordinate, y-coordinate)

10. Graph the following points: • (4, 2) • (4,-3) • (-4, -3)

11. If we have an equation with one variable, then the solution is the one number that makes the equation true. • If we have an equation with two variables, then the solutions are the pairs of values that make the equation true.

12. y = x + 2 Y= 5 and x = 3 would make this statement true along with y=6 and x=4, etc. There are many pairs that make this statement true. If we took those numbers and plotted them on a coordinate plane, they would form a straight line.

13. When graphing a line, you should find at least three pairs of values. • Make a chart to keep up with which numbers go together.

14. Example x y x y • y = x – 2 Fill in chart!

15. Now, graph the points on a coordinate plane.

16. Example x y Y = 2x + 1