# The straight line I

By the end of this topic you should be able to answer the following questions

- Can you calculate the gradient of the line connecting two points eg (4,2) and (-5,7)?
- Positive lines slope in which direction?
- Negative lines slope in which direction?
- What is the gradient of a line parallel to the x-axis?
- What is the gradient of a line parallel to the y-axis?
- What can you say about the gradients of lines which are parallel to each other?
- How are the gradient of a line and the angle it makes in the positive direction of the x-axis related?
- How are the gradients of perpendicular lines related?

The knowledge and methods used in this topic occur in later topics so please make the effort to master them.