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If 

where i=  ,  then what is A+B equal to?

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NDA-I (Mathematics) Official Paper (Held On: 13 Apr, 2025)
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  1. -10
  2. -6
  3. 0
  4. 6

Answer (Detailed Solution Below)

Option 2 : -6
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Detailed Solution

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Calculation:

Determinant Δ = 

Now, For our matrix, 

calculate the subdeterminants

⇒ 

⇒ 

⇒ 

⇒ Δ = 

⇒ Δ = 

⇒ 

Since we are given that  comparing the real and imaginary parts, we find:

A  = -6 and B = 0

Thus A + B = -6 + 0 = - 6

Hence, the Correct answer is Option 2.

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