NIMCET 2022 Mathematics PYQ — Let a = and b be another vector such that a b = 14 and a b = the … | Mathem Solvex | Mathem Solvex
Tip:A–D to answerE for explanationV for videoS to reveal answer
NIMCET 2022 — Mathematics PYQ
NIMCET | Mathematics | 2022
Let a = 2i^+2j^+k^ and b be another vector such that a ⋅ b = 14 and a × b = 3i^+j^−8k^ the vector b =
Choose the correct answer:
A.
5i^+j^+2k^
(Correct Answer)
B.
5i^−j^−2k^
Correct Answer:
5i^+j^+2k^
Explanation
Given a=2i^+2j^+k^. Check options with a⋅b=14. Only (a) 5i^+j^+2k^ gives 2(5)+2(1)+1(2)=14.<br> Now, a×(5i^+j^+2k^)=3i^+j^−8k^, matches. <br>5i^+j^+2k^<br>
Explanation
Given a=2i^+2j^+k^. Check options with a⋅b=14. Only (a) 5i^+j^+2k^ gives 2(5)+2(1)+1(2)=14.<br> Now, a×(5i^+j^+2k^)=3i^+j^−8k^, matches. <br>5i^+j^+2k^<br>
