Let and . Let be a vector such that and . Then is equal to
- (A)62
- (B)46✓ Correct
- (C)53
- (D)49
Answer: (B)
Solution
From , we get , so is parallel to .
Thus .
Using :
Using :
Solving these simultaneously with gives and .
So .
Now
Magnitude squared: .
Thus .
Using :
Using :
Solving these simultaneously with gives and .
So .
Now
Magnitude squared: .
JEE Main · 2023 · 12 Apr 2023 · Shift 1 · Single correct option