The diagonals of the parallelogram whose sides are $lx + my + n = 0,$ $lx + my + n' = 0$,$mx + ly + n = 0$, $mx + ly + n' = 0$ include an angle
The diagonals of the parallelogram whose sides are $lx + my + n = 0,$ $lx + my + n' = 0$,$mx + ly + n = 0$, $mx + ly + n' = 0$ include an angle
- A
$\frac{\pi }{3}$
- B
$\frac{\pi }{2}$
- C
${\tan ^{ - 1}}\left( {\frac{{{l^2} - {m^2}}}{{{l^2} + {m^2}}}} \right)$
- D
${\tan ^{ - 1}}\left( {\frac{{2lm}}{{{l^2} + {m^2}}}} \right)$
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- [JEE MAIN 2025]