NCERT Class 12 · Ch 10 Exercise 10.3 · Q9
NCERT Class 12 Maths · Chapter 10 Vector Algebra · Exercise 10.3 Question 9
For a unit vector a, (x−a)·(x+a)=12. Find |x|.
💡 Concept Hints
- Write the vector components and identify the required direction or geometric relation.
- Use the magnitude, dot-product, cross-product or section formula that matches the requested quantity.
✅ Step-by-Step Solution
Final Answer: √13.
- Expand the product: |x|²−|a|²=12.
- Since |a|²=1, |x|²=13 and |x|=√13.
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