If a , b , c are the direction ratios of a line L and , m, n are its direction cosines, then a^2 b^2+c^2 =

Step-by-step solution

Let a = 1 k , b = m k and c = n k aligned & a ^2 ~b ^2+ c ^2 = l ^2 ~m ^2+ n ^2 & = l ^2 1- p ^2 [ 1^2+ m ^2+ n ^2=1 ] aligned