3 3 3 4 SLOPE FINDING THE EQUATION
- Slides: 10
3. 3 & 3. 4 SLOPE & FINDING THE EQUATION OF A LINE Learning Goals • Find the slope of a line and graph a line given its slope and a point on it • Find the equation of a line given its slope and a point on the line, or two points, or its slope and the y-intercept
SLOPE • steepness of a line • the ratio of the vertical change to the horizontal change • “rise over run” *special cases: slope-intercept form: HOY VUX
EX 1 Find the slope. EX 2 Graph
EX 3 Graph
EX 4 Write an equation in slopeintercept form of the line that passes through EX 5 Find the slope of the line.
FORMULAS AND KEY INFO TO KNOW slope: slope-intercept form: slope of parallel lines: slope of perpendicular lines: point-slope form: standard form: *HOY *VUX
EX 6 Write an equation in point-slope form of the line with a slope of 3 and passing through EX 7 Write an equation in standard form of the line
EX 8 If the slope of a line is 3, find the slopes of lines parallel and perpendicular to the line. EX 9 Write an equation in slopeintercept form of the line that passes through the given point and is perpendicular to the given line.
EX 10 Write an equation in slope-intercept form of the line that passes through the given point and is parallel to the x -axis. EX 11
WRITING EQUATIONS OF LINES SUMMARY slope-intercept form Handy for graphing and comparing slopes Use when given: • slope & yintercept • point & slope • two points point-slope form Use when given: • point & slope • two points standard form Provides an easy way to find both intercepts and graph