The condition that the equation `lx +my +n = 0` represents the equatio of a straight line in the normal form is

Show that the equation lx+ my = 1(l ne 0,m ne 0) represents a straight line.

Assuming n to be negative , express the equation of the straight line lx+my+n=0 in the normal form.

Write the equation of normal form of a straight line.

The condition that the line lx +my+n =0 to be a normal to y^(2)=4ax is

The condition that the line lx +my+n =0 to be a normal to y^(2)=4ax is

If lx+my+nz=p is equation of a plane in normal form, then

If lx+my+nz=p is equation of a plane in normal form, then

The condition that the line lx+my+n=0 to touch the parabola y^(2)=4ax is

State the conditions under which the equation lx^(2)+2mxy+2px+2qy+r=0 represents a pair of lines

Show that the equation n(ax+by+c)=c(lx+my+n) represents the line joining the origin to the point of intersection of ax+by+c=0 and lx+my+n=0 .