List of top Mathematics Questions on angle between two lines asked in BITSAT

The angle between two lines in 3D space can be found using:
The angle between the lines whose intercepts on the axes are (a,-b) and (b,-a) respectively, is
What is the value of \( n \) so that the angle between the lines having direction ratios \( (1, 1, 1) \) and \( (1, 1, n) \) is \( 60^\circ \)?