Worked examples
Two examples
Example 1
A line is parallel to y = 3x + 2. What is its slope?
- Parallel lines have the same slope.
Answer: 3
Example 2
A line is perpendicular to y = 23x − 1. What is its slope?
- Perpendicular slopes are negative reciprocals: flip 23 and change its sign.
- Check: 23 × (−32) = −1.
Answer: −32
Where this is taught: Lines on the Grid, “Parallel and perpendicular”
The drill
Ten problems
How many:
Type each slope. A fraction like -2/3 is fine. Then press Check my answers at the bottom.Write each answer on the line. The answer key, with the reasoning, is on the last page.