Slope of a line and Conditions for Parallel and Perpendicula

Author:
Mathguru
On the screen, we see a straight line passing through points A and B with slope m. Observe how the values of the slope changes as we change the line by moving points A or B or both.
Question/s to think about. 1. What is the slope when the line is horizontal? 2. What is the slope when the line is vertical? 3. When is the slope positive? 4. When is the slope negative? 5. What is the angle that the line makes with the x-axis?