Class 12 Vector Algebra · Short Answer2 Markscross_product
Class 12 Maths · Vector Algebra · Short Answer #50
For r = (3,−2,6), evaluate (r × j) · (r × k) − 12.
✅ Step-by-Step Solution
Final Answer: 0.
- Compute r × j = (−6,0,3) and r × k = (−2,−3,0).
- The dot product is (−6)(−2) + 0(−3) + 3·0 = 12.
- Thus the expression equals 12 − 12 = 0.
📋 CBSE Stepwise Marking Scheme
- [0.5 marks] Compute r × j = (−6,0,3) and r × k = (−2,−3,0).
- [1 mark] The dot product is (−6)(−2) + 0(−3) + 3·0 = 12.
- [0.5 marks] Thus the expression equals 12 − 12 = 0.
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