Find value of | 368/21 vec u→u + 991/21 vec v→v - 1177/21 vec w→w | ?

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1 Answer
Ananda Dasgupta
Jun 12, 2018

85

Explanation:

367/21 vec u +991/21 vec v -1177/21 vec w36721→u+99121→v−117721→w
= 367/21(4,-1,7) +991/21(1,3,-2)-1177/21(2,2,-1)=36721(4,−1,7)+99121(1,3,−2)−117721(2,2,−1)

The three components are

  • 1/21 (367times 4+991times 1-1177times 2) = 5 121(367×4+991×1−1177×2)=5
  • 1/21 (367times (-1)+991times 3-1177times 2) = 12 121(367×(−1)+991×3−1177×2)=12
  • 1/21 (367times 7+991times (-2)-1177times (-1)) = 84 121(367×7+991×(−2)−1177×(−1))=84

Hence the required answer is

|(5,12,84)| = sqrt(5^2+12^2+84^2) = 85

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