Graphing with X and YIntercepts Learn to use
- Slides: 8
Graphing with X- and YIntercepts Learn to use x- and y-intercepts to graph linear equations.
You can graph a linear equation easily by finding the x-intercept and the y-intercept. The x-intercept of a line is the value of x where the line crosses the x-axis (where y = 0). The y-intercept of a line is the value of y where the line crosses the y-axis (where x = 0).
Find the x-intercept and y-intercept of the line y = 4 x + 4. Use the intercepts to graph the equation. Find the x-intercept (? , 0). y = 4 x + 4 (0) = 4 x + 4 -4 -4 -4 = 4 x -1 = x Find the y-intercept (0, ? ). y = 4 x + 4 y = 4(0) + 4 y =4 The x-intercept is (-1, 0). The y-intercept is (0, 4).
Plot both intercepts on the graph and draw in the line. The graph of y = 4 x + 4 is the line that crosses the x-axis at the point (-1, 0) and the y-axis at the point (0, 4).
Find the x-intercept and y-intercept of the line y = -3 x - 6. Use the intercepts to graph the equation. Find the x-intercept (? , 0). Find the y-intercept (0, ? ). y = -3 x - 6 (0) = -3 x - 6 +6 _ +6 6 = -3 x -2 = x y = -3 x - 6 y = -3(0) - 6 y = -6 The x-intercept is (-2, 0). The y-intercept is (0, -6).
Plot both intercepts on the graph and draw in the line. The graph of y = -3 x – 6 is the line that crosses the x-axis at the point (-2, 0) and the y-axis at the point (0, – 6).
Find the x-intercept and y-intercept of the line y = 18 – 6 x. Use the intercepts to graph the equation. Find the x-intercept (? , 0). y = 18 – 6 x Find the y-intercept (0, ? ). (0)= 18 – 6 x y = 18 – 6 x 0 = 18 – 6 x y = 18 – 6(0) -18 y = 18 -18 = – 6 x x=3 The x-intercept is (3, 0). The y-intercept is (0, 18).
Plot both intercepts on the graph and draw in the line. The graph of y = 18 – 6 x is the line that crosses the x-axis at the point (3, 0) and the y-axis at the point (0, 18).