Class 12 Vector Algebra · Conceptual Answer1 Marksvector_identities
Class 12 Maths · Vector Algebra · Conceptual Answer #100
Given |a×b|²+(a·b)²=400 and |a|=5, find |b|.
✅ Step-by-Step Solution
Final Answer: 4
- Lagrange’s identity gives 25|b|²=400, hence |b|²=16 and |b|=4.
- 4
📋 CBSE Stepwise Marking Scheme
- [0.5 marks] Lagrange’s identity gives 25|b|²=400, hence |b|²=16 and |b|=4.
- [0.5 marks] 4
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