Question

= + 2, =++, = 7– 3+ 4, then the vector satisfies the relation × = × , . = 0 is given by –

• A. 2+ 4+
• B. 2– 8–
• C. 2+ 5+2
• D. None of these

Answer 1

Answer: (B)

2– 8–

Answer 2

× = ×

Ž (–) ×= 0 Ž = + l

Ž = (7+ l) + (–3 + l) + (4 + l)

Ž $\vec { a }$ . = 0 Ž 7 + l + 2(4 + l) = 0

Ž l = – 5 So = 2 – 8 –