Lesson eLearning

Which of the following is the dot product of (mathbf{a}=(2,,-3,,5)) and (mathbf{b}=(-4,,1,,2))?

easy MCQ 1 mark Class 12 · Mathematics · Vector Algebra
  1. -1
  2. 1
  3. 3
  4. -3
Answer
-1

The correct answer is -1 — Add the products: (-8+(-3)+10=-1).

Step-by-step solution

  1. Identify the components of (mathbf{a}) and (mathbf{b}).
  2. Multiply corresponding components: (2\times(-4)=-8), ((-3)\times1=-3), (5\times2=10).
  3. Add the products: (-8+(-3)+10=-1).
Common mistake: forgetting the sign of a component in the multiplication

Concept tested: dot product

Published · How this solution was prepared and checked

← All Vector Algebra questions