If $\theta$ is the angle between the vectors $\vec{a} = 2\hat{i} + 2\hat{j} - \hat{k}$ and $\vec{b} = 6\hat{i} - 3\hat{j} + 2\hat{k}$,then:

  • A
    $\cos \theta = \frac{4}{21}$
  • B
    $\cos \theta = \frac{3}{19}$
  • C
    $\cos \theta = \frac{2}{19}$
  • D
    $\cos \theta = \frac{5}{21}$

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