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JEE Mains · Maths · STD 12 - 11. three dimension geometry
The acute angle between two lines such that the direction cosines \(l, m, n,\) of each of them satisfy the equations \(l+ m + n = 0\) and \(l^2 + m^2 - n^2 = 0\) is ..…… \(^o\)
- A \(15\)
- B \(30\)
- C \(60\)
- D \(45\)
Answer & Solution
Correct Answer
(C) \(60\)
Step-by-step Solution
Detailed explanation
Let \(l_{1}, m_{1}, n_{1}\) and \(l_{2}, m_{2}, n_{2}\) be thed.c of line \(1\) and \(2\) respectively, then as given \(l_{1}+m_{1}+n_{1}=0\) and \(l_{2}+m_{2}+n_{2}=0\) and \(l_{1}^{2}+m_{1}^{2}-n_{1}^{2}=0\) and \(l_{2}^{2}+m_{2}^{2}-n_{2}^{2}=0\)…
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