Presentation on theme: "Objective: Use slope-intercept form and standard form to graph equations. 2.4 Quick Graphs of Linear Equations."— Presentation transcript:
Objective: Use slope-intercept form and standard form to graph equations. 2.4 Quick Graphs of Linear Equations
Vocabulary y-intercept: the y-coordinate of a point where a graph intersects the y-axis Where the graph crosses the y-axis Slope-intercept form: a linear equation of the form y=mx+b
Graphing Equations in Slope-Intercept Form 1. Write the equation in slope-intercept form by solving for y. 2. Find the y-intercept and plot the corresponding point. 3. Find the slope and use it to plot a second point on the line. 4. Draw a line through the two points.
Standard Form An x-intercept is the x-coordinate of a point where a graph intersects the x-axis. Every linear equation can be written in the standard form Ax + By = C where A and B are not both zero.
Graphing Equations in Standard Form 1. Write the equation in standard form. 2. Find the x-intercept by letting y=0 and solving for x. Plot the corresponding point. 3. Find the y-intercept by letting x=0 and solving for y. Plot the corresponding point. 4. Draw a line through the two points.
Parallel and Perpendicular Lines Two lines are parallel if they lie in the same plane and never intersect. Two lines are perpendicular if they intersect to form a right angle.
Slopes of Parallel & Perpendicular Lines The lines are parallel if and only if they have the same slope. m 1 = m 2 The lines are perpendicular if and only if their slopes are negative reciprocals of each other. m 1 = 2 m 2 = −½
Homework: Complete on a separate piece of paper.