If [itex]\vec{OA}[/itex] is the unit vector [itex]l_1i+m_1j+n_1k[/itex] and [itex]\vec{OB}[/itex] is the unit vector [itex]l_2i+m_2j+n_2k[/itex], by using the cosine formula in triangle OAB find the angle between [itex]\vec{OA}[/itex] &[itex]\vec{OB}[/itex]..(adsbygoogle = window.adsbygoogle || []).push({});

I have tried expressing them as direction cosines , but none of that is working..can anyone point me in the right direction..

Also I have not been introduced to scalar product ..is there an easy way of go about doing this without using the scalar product

Thanks

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# Finding the angle of unit vectors

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