Find the acute angle between the two straight lines whose direction cosines are given by `l+m+n=0` and `l^2+m^2-n^2=0`

Find the acute angle between the two straight lines whose direction cosines are given by l+m+n=0, l^(2)+m^(2)-n^(2)=0

Find the angle between the two straight lines whose direction cosines are given by 2l+2m-n=0, mn+nl+lm=0

Find the acute angle between the two straight lines whose direction cosines are given by 3l+m+5n=0, 6mn-2nl+5lm=0

Find the angle between the two straight lines whose direction cosines are given by l+2m+3n=0, 3lm-4ln+mn=0

Find the acute angle vetween two straight lines whose direction cosines are given by the equations l-5m+3n=0 and 7l^(2)+5m^(2)-3n^(2)=0

Find the angle betwween the two straight lines whose direction l,m,n are given by 2l+2m-n=0 and mn+nl;+lm=0

The acute angle between the two lines whose direction ratios are given by l+m-n=0 " and " l^(2)+m^(2)-n^(2)=0 is

Prove that the acute angle between the lines whose direction cosines are given by the relation l+ m+n=0 and l^2+m^2-n^2=0 and pi/3