NCERT Class 12 · Ch 11 Exercise 11.2 · Q3
NCERT Class 12 Maths · Chapter 11 Three Dimensional Geometry · Exercise 11.2 Question 3
Show that the line through (4,7,8),(2,3,4) is parallel to that through (−1,−2,1),(1,2,5).
💡 Concept Hints
- Identify the base point and a nonzero direction before applying a vector formula.
- Use dot products for angles, proportional directions for parallelism, and a triple product for skew-line distance.
✅ Step-by-Step Solution
Final Answer: The lines are parallel.
- The two displacements are (−2,−4,−4) and (2,4,4).
- They are negatives of each other, so the direction vectors are proportional and the lines are parallel.
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