What is the angle between the straight line and the plane ?

Answer and explanation

Correct answer: A.

  1. Step 1: The direction vector of the line is and the normal to the plane is .
  2. Step 2: The angle between a line and a plane satisfies .
  3. Step 3: Compute: . Magnitudes: , and . Thus .
Answer
.
Why not the others: is the angle between the line and the normal to the plane (); subtracts incorrectly; confuses cosine and sine.

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