Project dossier Oeganda :: Owangai - Livingstone

Chapter 2 Section 3: Linear Functions and Their GraphsThe y-Intercept of a LineThe y -intercept is the point where the line crosses the y -axis. The y -intercept always occurs whenx = 0 , since any point on the y -axis has an x -coordinate of 0, as shown.When you plug x = 0 into the equation y = mx + b , you get:y = 0 + by = b ,which is, therefore, the y -intercept of the line.The Effect of the y-InterceptIn an animation in the course online, m is set equal to 1 2, while b varies.Note: View the animation in the course online.The Effect of the SlopeIn another animation in the course online, b is set equal to 1 2, while m varies.Note: View the animation in the course online.Example GFind the slope and the y -intercept of the line with this equation: y = 5x+ 7.First, notice that the equation is in slope-intercept form, y = mx + b .So, the slope is m = 5 , and the y -intercept is b = 7 .When we say “the y -intercept is 7 ,” we mean that the line crosses the y -axis at the point0, 7 .( 0, 7 ); we can also say that the y -intercept is the point ( )Since the equation given was in slope-intercept form, we just had to look at the equation to seeour answer.Page 6 of 9