Equation of a line Graphing lines Matching Lines Review Equation of a line Graphing lines Matching

Y=mx+b What is the equation of a line? What do the variables stand for? Y=mx+b m is the slope of the line – rise over run, stairs b is the y intercept, where the graph starts x and y are the coordinates of the points the line goes through, they stay as variable

Lines and Slopes Describe a positive sloping line Describe a negative sloping line Slope of a Horizontal line Slope of a Vertical line Line the goes up from left to right Line that goes down from left to right Line does not go up or down, has a slope of 0 Line that goes up and down with no left or right movement, slope is undefined

Graphing Lines Need at least 2 points to draw a line Plot y-intercept (b value) From y-intercept do slope – rise over run

Graphs and Lines How would you match an equation of a line to the graph of a line? What are some key things you look for?

Intercepts What are intercepts of lines? Where line crosses x or y axis, could be when any two lines cross How do you find the x-intercept? Find x value in table when y=0 Sub in 0 for y in equation and solve, we will talk about this How do you find the y-intercept? Find y value in table when x=0 Sub in 0 for x and solve for y You can always look on graph

Slope Rise of the Line over the run of the line Stairs on the graph from one point to the other Constant Pattern in the table of data

Homework Worksheet on Slopes and intercepts