[" The line "lx+my+n=0" intersects the curve "ax^(2)+2hxy+by^(2)=1" at the point "P" and "Q" .The circle on "],[" PQ as diameter passes through the origin.Prove that "n^(2)(a+b)=l^(2)+m^(2)" ."]

The line lx+my+n=0 intersects the curve ax^(2)+2hxy+by^(2)=1 at the point P and Q. The circle on PQ as diameter passes through the origin.Then n^(2)(a+b) equals (A) l^(2)+m^(2)(B)2lm(C)l^(2)-m^(2)(D)4lm

The line lx+my+n=0 intersects the curve ax^2 + 2hxy + by^2 = 1 at the point P and Q. The circle on PQ as diameter passes through the origin. Then n^2(a+ b) equals (A) l^2+m^2 (B) 2lm (C) l^2-m^2 (D) 4lm

The line 3x+6y=k intersects the curve 2x^(2)+3y^(2)=1 at points A and B .The circle on AB as diameter passes through the origin. Then the value of k^(2) is

The line 3x+6y=k intersects the curve 2x^2+3y^2=1 at points A and B . The circle on A B as diameter passes through the origin. Then the value of k^2 is__________

The line 3x+6y=k intersects the curve 2x^2+3y^2=1 at points A and B . The circle on A B as diameter passes through the origin. Then the value of k^2 is__________

If line lx+my+n=0 is perpendicular to one of the lies ax^(2)+2hxy+by^(2)=0 then

The line lx+my+n=0 touches y^(2)=4ax

If the line lx + my = 1 is a tangent to the circle x^(2) + y^(2) = a^(2) , then the point (l,m) lies on a circle.

If the line lx+my-1=0 touches the circle x^(2)+y^(2)=a^(2), then prove that (l,m) lies on a circle.