Passage
Let be the origin, and be three unit vectors in the directions of the sides , respectively, of a triangle .Let be the origin, and be three unit vectors in the directions of the sides , respectively, of a triangle .
If the triangle varies, then the minimum value of
is
If the triangle varies, then the minimum value of
is
- (A)
- (B)✓ Correct
- (C)
- (D)
Answer: (B)
Solution
Since , we have:
Similarly, and .
So the expression becomes:
Now:
Since , we have:
Therefore:
The minimum value is , achieved when .
Similarly, and .
So the expression becomes:
Now:
Since , we have:
Therefore:
The minimum value is , achieved when .
JEE Advanced · 2017 · 21 May 2017 · Paper 2 · Single correct option