The straight lines, whose direction cosines are `l, m, n` which are the roots of `al+bm+cn=0` and `fl^2+gm^2+hn^2=0` are parallel

Show that the straight lines whose direction cosines are given by the equations al+bm+cn=0 and u l^2+z m^2=v n^2+w n^2=0 are parallel or perpendicular as a^2/u+b^2/v+c^2/w=0 or a^2(v +w)+b^2(w+u)+c^2(u+v)=0

Show that the straight lines whose direction cosines are given by the equations al+bm+cn=0 and u l^2+v m^2+w n^2=0 are parallel or perpendicular as a^2/u+b^2/v+c^2/w=0 or a^2(v +w)+b^2(w+u)+c^2(u+v)=0

Show that the straight lines whose direction cosines are given by the equations al+bm+cn=0 and u l^2+v m^2+w n^2=0 are parallel or perpendicular as a^2/u+b^2/v+c^2/w=0 or a^2(v +w)+b^2(w+u)+c^2(u+v)=0

Show that the straight lines whose direction cosines are given by al+bm+cn=0 and pl^(2)+qm^(2)+rn^(2)=0 are parallel if a^(2)/p+b^(2)/q+c^(2)/r=0 .

Prove that the straight lines whose direction cosines are given by the equations al+bm+cn=0 and fmn+gnl+hlm=0 are parallel if a^(2)f^(2)+b^(2)g^(2)+c^(2)h^(2)-2(abfg+bcgh+cahf)=0

A straight line L with direction cosines l, m, n is parallel to 3x-4y+2z+8=0 where

Prove that the straight lines whose direction cosines are given by the equations al+bm+cn=0 and fmn+gnl+hlm=0 are at right angles if f/a+g/b+h/c=0

The straight lines whose direction cosines are given by al+bm+cn=0 ,fmn+gnl+hlm=0 are perpendicular if