Presentation on theme: "4.7 Graphing Lines Using Slope Intercept Form"— Presentation transcript:
1 4.7 Graphing Lines Using Slope Intercept Form Goal: Graph lines in slope intercept form.
2 Slope-Intercept Form of the Linear Equation y = mx + bmb= slope= y-interceptAny linear equation which is solved for y is in slope-intercept form.
3 Find the slope and y-intercept of the following linear equations: y = -2x - 1y = 3x + 4m = -2b = -1m = 3b = 4-21y = x -y = 5x94-2-1m =m = 5b = 0b =94
4 Write a linear equation in the form y = mx + b given the following. m = 2, b = -3y = 2x - 3m = , b = 5
5 -2 -3 Graph the following linear equation using slope and y-intercept. Stepsy1) Find the slope and y-intercept.+3+2x2) Plot the y-intercept.-23) Plot the slope.-2-32m =or m =-334) Draw line through points.
6 Graph the line which passes through (-2, 1) and has a slope of -3. Stepsy1) Plot the point.2) Write slope as fractionand count off other points.-3m = -3-3x=13+1or m =-13) Draw line through points.
7 -3 -4 Graph the line which passes through (3, 2) and has a slope of . Stepsy+41) Plot the point.+32) Write slope as fractionand count off other points.3xm =4-3or m =-43) Draw line through points.
8 Write a linear equation in slope-intercept form to describe each graph. y = mx + byy8xx-624b = -4b = 3y = 2x + 3
9 Sometimes we must solve the equation for y before we can graph it. The constant, b = 3 is the y-intercept.The coefficient, m = -2 is the slope.
10 1) Plot the y-intercept as a point on the y-axis 1) Plot the y-intercept as a point on the y-axis. The constant, b = 3, so the y-intercept = 3.down 22) Plot more points by counting the slope up the numerator (down if negative) and right the denominator. The coefficient, m = -2, so the slope = -2/1.right 1down 2right 1
11 Parallel Lines Graph the following on the coordinate plane. yxParallel lines have the same slope.
12 Lines are parallel! Same slope! Tell whether the lines below are parallel.1) 3x + y = y = -3x + 1-3x xy = -3x + 7m = -3y = mx + bSame slope!m = -3Lines are parallel!