In this Section:
In this section, we continue to learn about the slope of a line. Now we will learn a quicker method to find the slope of a line. Instead of using the slope formula, we will solve our equation for y and observe the slope as the coefficient of x. This form of a line is known as slope-intercept form: y = mx + b. When we have a line in slope-intercept form, the slope is given as m, and our y - intercept is given as the point (0,b). Using this information, we can quickly graph the equation. Plot the y-intercept as the first point, then use the slope to find as many additional points as you would like. We can then draw a straight line though the points and place arrows at each end. Additionally, we will learn how to determine if two lines are parallel or perpendicular. Two lines are parallel, if they have the same slope, but different y-intercepts. Two lines are perpendicular, if the product of their slopes is -1. We can easily determine if lines are parallel or perpendicular by placing the lines in slope-intercept form. This allows us to quickly observe the slope and see if the slopes are the same (parallel) or their product is -1 (perpendicular).