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NDA 2010
Exam
NDA
Year
2010
Subject
Mathematics
Chapter
Vector Algebra

NDA 2010 · Mathematics · Vector Algebra

What is the geometric interpretation of the identity ( a - b ) ×( a...

What is the geometric interpretation of the identity (a⃗−b⃗)×(a⃗+b⃗)=2(a⃗×b⃗)?(\vec{a}-\vec{b}) \times(\vec{a}+\vec{b})=2(\vec{a} \times \vec{b}) ? I. If the diagonals of a given parallelogram are used as sides of a second parallelogram, then the area of the second parallelogram is twice that of the given parallelogram. II. If the semi-diagonals of a given parallelogram are used as sides of a second parallelogram, then the area of the second parallelogram is half that of the given parallelogram. Select the correct answer using the code given below:

Options

  1. AI only
  2. BII only
  3. CBoth I and II
  4. DNeither I nor II

Correct answer

C. Both I and II

Step-by-step solution

The correct answer is option (C).
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