The two products

Exercise and reference answers

Questions

1. Question

   a · b equals

   Choices

   1. |a||b| sin θ
   2. |a| + |b|
   3. |a||b| cos θ

   Correct choice

   |a||b| cos θ

2. Question

   The magnitude of a × b involves

   Choices

   1. sin θ
   2. cos θ
   3. tan θ

   Correct choice

   sin θ

3. Question

   a × b points

   Choices

   1. along a
   2. perpendicular to both a and b
   3. along b

   Correct choice

   perpendicular to both a and b

4. Question

   In component form a · b equals

   Choices

   1. a₁b₁ − a₂b₂ + a₃b₃
   2. a₁ + b₁
   3. a₁b₁ + a₂b₂ + a₃b₃

   Correct choice

   a₁b₁ + a₂b₂ + a₃b₃

Explanation