Let $| \mathbf { a } | = 1$ and $| \mathbf { b } | = 2$ and the angle between a and b be 150°. Find
(i) $\mathbf { a } \cdot \mathbf { b }$ (ii) $\mathbf { b } \cdot ( 3 \mathbf { a } + \mathbf { b } )$ (iii) $( \mathbf { a } + \mathbf { b } ) \cdot ( \mathbf { a } - \mathbf { b } )$ (iv) $| 2 a - b | ^ { 2 }$

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The Answer of Let $| \mathbf { a } | = 1$ and $| \mathbf { b } | = 2$ and the angle between a and b be 150°. Find
(i) $\mathbf { a } \cdot \mathbf { b }$ (ii) $\mathbf { b } \cdot ( 3 \mathbf { a } + \mathbf { b } )$ (iii) $( \mathbf { a } + \mathbf { b } ) \cdot ( \mathbf { a } - \mathbf { b } )$ (iv) $| 2 a - b | ^ { 2 }$

Let ∣a∣=1| \mathbf { a } | = 1∣a∣=1 And ∣b∣=2| \mathbf { b } | = 2∣b∣=2

Let $| \mathbf { a } | = 1$ And $| \mathbf { b } | = 2$