If straight line `lx + my + n=0` is a tangent of the ellipse `x^2/a^2+y^2/b^2 = 1,` then prove that `a^2 l^2+ b^2 m^2 = n^2.`

Find the area of the ellipse x^(2)/a^(2)+y^(2)/b^(2)=1

The area enclosed by the ellipse x^2/a^2+y^2/b^2=1 is :

The line l x+m y-n=0 is a normal to the hyperbola (x^2)/(a^2)-(y^2)/(b^2)=1 . then prove that (a^2)/(l^2)-(b^2)/(m^2)=((a^2-b^2)^2)/(n^2)

The line L x+m y+n=0 is a normal to the ellipse (x^(2))/(a^(2))+(y^(2))/(b^(2))=1 , if

If any tangent to the ellipse x^2/a^2+y^2/b^2=1 cuts off intercepts of length h and k on the axes, then a^2/h^2+b^2/k^2 =

The line x+y=a will be a tangent to the ellipse (x^(2))/(9)+(y^(2))/(16)=1 , if a=

The condition that y=m x+c is a tangent to the ellipse (x^(2))/(a^(2))+(y^(2))/(b^(2)) =1 is

The st line lx+my+n=0 will be a tangent to the parabola y^(2)=4bx if

If the straight line xcosalpha+ysinalpha=p touches the curve (x^2)/(a^2)+(y^2)/(b^2)=1, then prove that a^2cos^2alpha+b^2sin^2alpha=p^2dot

If the straight line xcosalpha+ysinalpha=p touches the curve (x^2)/(a^2)-(y^2)/(b^2)=1, then prove that a^2cos^2alpha-b^2sin^2alpha=p^2dot