Reading the definitions back

Exercise and reference answers

Questions

1. Question

   Slope of a horizontal line

   Choices

   1. undefined
   2. one
   3. zero

   Correct choice

   zero

2. Question

   Slope of a vertical line

   Choices

   1. undefined
   2. zero
   3. infinite and defined

   Correct choice

   undefined

3. Question

   If a line makes angle α with the x-axis, its slope is

   Choices

   1. sin α
   2. tan α
   3. cos α

   Correct choice

   tan α

4. Question

   Three points are collinear when

   Choices

   1. slopes multiply to −1
   2. slopes differ
   3. slope AB = slope BC

   Correct choice

   slope AB = slope BC

Explanation