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AP EAMCET202018 Sep 2020Evening ShiftMathematicsVector AlgebraActual

Find ' ( ) ' if ( a , b , c ) are three non-coplanar vectors such that ( [ array ccc 4 a+3 b-c & 4 a+3 b+2 c a-4 b-c array ] ) (= ( ^2+ +1 ) [ array lll a & b & c array ] )

Options

  1. A(-7,8 )
  2. B(-7,-6 )
  3. C(7,-8 )
  4. D(-7,-8 )

Correct answer

C. (7,-8 )

Step-by-step solution

( array rlrl | array ccc 4 & 3 & -1 4 & 3 & 2 1 & -4 & -1 array |[ a b c ] & = ( ^2+ +1 )[ a b c ] 4(5)-3(-6)-1(-19) & = ^2+ +1 57 & = ^2+ +1 & & ^2+ -56 & =0 & & ( -7)( +8) & =0 & & & =7 (or) -8 array ) Hence, option (c) is correct.

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