The angle between two lines having direction ratios 1, 1, 2 and 4 is

Question

Philoid · Accepted Answer

Let <img w='399' height='28' src='https://static.philoid.co/ncertusercontent/solutions/images/PROJ33329/1561113526452371.png' style='vertical-align: middle;'> <img w='404' height='46' src='https://static.philoid.co/ncertusercontent/solutions/images/PROJ33329/1561113527180177.png' style='vertical-align: middle;'> <img w='403' height='58' src='https://static.philoid.co/ncertusercontent/solutions/images/PROJ33329/1561113527889155.png' style='vertical-align: middle;'> <img w='221' height='47' src='https://static.philoid.co/ncertusercontent/solutions/images/PROJ33329/1561113528603912.png' style='vertical-align: middle;'> <img w='72' height='42' src='https://static.philoid.co/ncertusercontent/solutions/images/PROJ33329/156111352941662.png' style='vertical-align: middle;'> <img w='60' height='23' src='https://static.philoid.co/ncertusercontent/solutions/images/PROJ33329/1561113530120388.png' style='vertical-align: middle;'>