1. Finding the Slopes of Lines Lines and Their Slopes

2. Learning Objectives You will be able to identify the x-intercept and y-intercepts from a graph of a line, as well as, calculate the intercepts from the equation of a line. You will be able to calculate the slope of a line. You will be able to identify the x-intercept and y-intercepts from a graph of a line, as well as, calculate the intercepts from the equation of a line. You will be able to calculate the slope of a line.

3. What is a line? A line is straight and can have a slant, or can be vertical, or can be horizontal. Each type of line has different graphs, slopes, and equations. Slanted lineVertical lineHorizontal line

4. How do I find the intercepts from a graph of a line? The x-intercept is the place the line crosses the x- axis. That point has the form (x, 0). The y-intercept is the place the line crosses the y-axis. That point has the form (0, y). Horizontal lines only have a y-intercept and vertical lines only have an x-intercept. The x-intercept is the place the line crosses the x- axis. That point has the form (x, 0). The y-intercept is the place the line crosses the y-axis. That point has the form (0, y). Horizontal lines only have a y-intercept and vertical lines only have an x-intercept.

5. What is the slope? The slope tells us the slant of the line. It is a ratio of the vertical displacement (rise) divided by the horizontal displacement (run). The slope of a horizontal line has no vertical displacement (rise), so the slope/slant is zero, and this graphically makes sense. The slope of a vertical line has no horizontal displacement, so we say the slope is undefined. The slope tells us the slant of the line. It is a ratio of the vertical displacement (rise) divided by the horizontal displacement (run). The slope of a horizontal line has no vertical displacement (rise), so the slope/slant is zero, and this graphically makes sense. The slope of a vertical line has no horizontal displacement, so we say the slope is undefined.

6. How do we find the slope? For a slanted line the slope is calculated using two points on a line. The slope is: the change in y (rise) divided by the change in x (run). We derive the formula by calculating the difference of the y- coordinates divided by the difference in the x-coordinates. For a slanted line the slope is calculated using two points on a line. The slope is: the change in y (rise) divided by the change in x (run). We derive the formula by calculating the difference of the y- coordinates divided by the difference in the x-coordinates.

7. What is the formula for slope? The slope is formally denoted by m and is found by dividing the change in y by the change in x. To calculate the slope you must be given two points on the line. You calculate slope using: