If `l,m,n` are the d.c's of a vector if `l=1/2` then maximum value of `lmn=`

If l,m,n are d .c's of vector bar(OP) then maximum value of lmn is

If l, m, n are d.c's of vector bar(OP) then maximum value of lmn is

If (l,m,n) are the direction cosines of a line, find the maximum value of the product lmn.

If l,m,n are the direction cosines of a half line op then the maximum value of l.m.n is

if e=vec li+mvec j+nvec k is a unit vector and l=(1)/(3) then the maximum value of lmn is

If l^(2) + m^(2) =1 , then the maximum value of l+m is

If (l_(1),m_(1),n_(1)),(l_(2),m_(2),n_(2)) are d.c's of two lines then find the value of (l_(1)m_(2)-l_(2)m_(1))^(2)+(m_(1)n_(2)-n_(1)m_(2))^(2)+(n_(1)l_(2)-n_(2)l_(1))^(2)+(l_(1)l_(2)+m_(1)m_(2)+n_(1)n_(2))^(2)

If l , m, n are the direction cosines of a line, then: a) l^(2)+m^(2)+n^(2)=1 b) l^(2)+m^(2)+n^(2)=0 c) l+m+n=1 d) l+m+n=0