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GATE 2024 MN – Question 43

Engineering Mathematics · Vector Calculus · 2 marks · Multiple choice

Triangle sides are a=(2, 3, −4), b=(4, 2, 3). Find triangle area and a unit normal.

  1. 28.93; (0.58, −0.76, −0.27)
  2. 28.93; (17, −22, −8)
  3. 14.46; (0.58, −0.76, −0.27)
  4. 14.46; (17, −22, −8)

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Show answer and explanation

Correct answer: (C) 14.46; (0.58, −0.76, −0.27)

Explanation

The cross product is a×b=(17, −22, −8), whose magnitude is√837≈28.93. Triangle area is half that, 14.46. Normalising gives approximately(0.588, −0.760, −0.277), matching C. The unnormalised cross product is not a unit vector.

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