Join the Most Relevant JEE Main 2025 Test Series & get 99+ percentile! Join Now
Search any question & find its solution
Question: Answered & Verified by Expert
The value of (a×b)2+(a·b)22(a)2(b)2 is
MathematicsVector AlgebraAP EAMCETAP EAMCET 2021 (20 Aug Shift 2)
Options:
  • A 0
  • B 1
  • C 12
  • D 14
Solution:
1469 Upvotes Verified Answer
The correct answer is: 12

Given, (a×b)2+(a·b)22(a)2(b)2

We know, (a)2=a·a=a2, (a×b)2=a2b2sin2θ, (a·b)2=a2b2cos2θ

Where, a=a, b=b

=a2b2sin2θ+a2b2cos2θ2a2b2

=a2b2(sin2θ+cos2θ)2a2b2

=12

Looking for more such questions to practice?

Download the MARKS App - The ultimate prep app for IIT JEE & NEET with chapter-wise PYQs, revision notes, formula sheets, custom tests & much more.