Vectors - Magnitude of a Vector

Vectors - Magnitude of a Vector

  1. Given \(\mathbf{a}\) is a unit vector and \(\mathbf{b}\) is a vector such that \(|\mathbf{b}|=3\), and that the angle between \(\mathbf{a}\) and \(\mathbf{b}\) is \(\theta=30^\circ\), find the value of \(\mathbf{a}\cdot\mathbf{b}\) in exact form.
  2. Another vector \(\mathbf{c}\) is such that \(\mathbf{c}=\mathbf{a}-\mathbf{b}\). Find the exact magnitude of \(\mathbf{c}\).

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Answer:(i) \(\frac{3\sqrt{3}}{2}\) (ii) \(|\mathbf{c}| = \sqrt{10 - 3\sqrt{3}}\)

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