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Let  be unit vectors. What is  equal to?

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NDA-I (Mathematics) Official Paper (Held On: 13 Apr, 2025)
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Answer (Detailed Solution Below)

Option 1 : 0
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Detailed Solution

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Calculation:

Given,

The vectors  are unit vectors.

Since  and   are unit vectors, we know:

.

The magnitude of the cross product  is given by:

.

Since , we have:

, so , meaning and  are perpendicular.

The dot product is:

.

∴ The value of is 0.

Hence, the correct answer is Option 1.

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