If l_1 , m_1 , n_1 and l_2 , m_2 , n_2 be the direction cosines of two mutually perpendicular lines, then the dire

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Q 1247512483.     If l_1 , m_1 , n_1 and l_2 , m_2 , n_2 be the direction cosines of two mutually perpendicular lines, then the direction cosines of the line perpendicular to both the lines are:
A

m_1 n_2 + m_2 n_1 , n_1 l_2 + n_2 l_1 , l_1 m_2 + l_2 m_1

B

l_1 l_2 , m_1 m_2 , n_1 n_2

C

none of these

D

m_1 n_2 - m_2 n_1 , n_1 l_2 - n_2 l_1 , l_1 m_2 - l_2 m_1

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