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AP EAMCET2003MathematicsVector Algebra

If a = i + j + k , b = i + j , c = i and ( a b ) c = a + b , then + is equal to:

Options

  1. A0
  2. B1
  3. C1
  4. D3

Correct answer

A. 0

Step-by-step solution

We have a b = | array ccc i & j & k 1 & 1 & 1 1 & 1 & 0 array |= i (-1)- j (-1)+ k (1-1)=- i + j ( a b ) c = | array rrr i & j & k -1 & 1 & 0 1 & 0 & 0 array |= k (-1)=- k Now, a + b = ( i + j + k )+ ( i + k )=( + ) i +( + ) j + k a + b =( a b ) c ( + ) i +( + ) j + k =- k Equating the coefficient of i + =0

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