What is the angle between the two 3D vectors and ?

Answer and explanation

Correct answer: B. ( radians)

  1. Step 1: Compute dot product: .
  2. Step 2: Compute magnitudes: , .
  3. Step 3: \cos\theta = \frac{\vec{a} \cdot \vec{b}}{|\vec{a}||\vec{b}| = \frac{1}{\sqrt{2} \times \sqrt{2}} = \frac{1}{2}.
  4. Step 4: radians.
Answer
60 degrees (pi/3 radians).
Why not the others: '' is for ; '' would require orthogonal dot product 0.

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