CBSE Class 12 Mathematics 2026 Main Paper 65/3/2 · Q81 Marksdot_products
CBSE Class 12 Mathematics 2026 Main Paper 65/3/2 · Question 8 (Vector Algebra)
If (a+b)·(a−b)=198 and |a|=10|b|, choose the true statement.
✅ Step-by-Step Solution
Final Answer: |b|=√2
- The mixed terms cancel, leaving |a|²−|b|²=99|b|²=198. Thus |b|=√2.
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