Mathbee CBSE Mathbee · CBSE Class 12 Maths
Class 12 Vector Algebra · Short Answer2 Marksorthogonality

Class 12 Maths · Vector Algebra · Short Answer #57

For a = (1,2,−3), b = (3,−1,2), show a + b is perpendicular to a − b.

✅ Step-by-Step Solution

Final Answer: (a + b) ⟂ (a − b).
  1. Compute a + b = (4,1,−1) and a − b = (−2,3,−5).
  2. Their dot product is −8 + 3 + 5 = 0.
  3. Both are nonzero, so a + b and a − b are perpendicular.

📋 CBSE Stepwise Marking Scheme

  • [0.5 marks] Compute a + b = (4,1,−1) and a − b = (−2,3,−5).
  • [1 mark] Their dot product is −8 + 3 + 5 = 0.
  • [0.5 marks] Both are nonzero, so a + b and a − b are perpendicular.

Master Chapter 10: Vector Algebra

Practise interactive questions, flashcards, visual mind maps, and timed board tests for Vector Algebra.
📘 Chapter Notes & All Exercises 🚀 Open in Interactive Workspace →
← Previous Question
Find all vectors of magnitude 6 perpendicular to both (2,−1,2) and…
Next Question →
Prove |a × b|² = |a|²|b|² − (a · b)² for any vectors a,b.

More Practice Questions in Vector Algebra

Related Questions in Vector Algebra