Find the equation of the directrices of the ellipse `x^2/25+y^2/9=1`.

Find the equation of the tangents to the ellipse 3x ^2 + 4y ^2 = 12 which are perpendicular to the line 2x +y - 4 = 0.

Find the coordinates of vertices,the foci,the eccentricity and the equations of the directrix of the following hyperbola. x^2/16-y^2/9=1 .

Find the coordinates of the centre, vertices, foci and the equation to the directrices of (ii) 9x ^2 + 25y ^2 = 225

Find the coordinates of the centre, vertices, foci and the equation to the directrices of (iii) 4x ^1 + 5y ^2 = 1

Find the equation of the diameter of the circle x ^2 + y ^2 - 14x + 6y + 9 = 0 which passes through the point (2, 1).

Find the coordinates of vertices,the foci,the eccentricity and the equations of the directrix of the following hyperbola. 16x^2-9y^2=576 .

Find the coordinates of the centre, vertices, foci and the equation to the directrices of (i) 2x ^2 + 5y ^ = 10

Find the equations of the tangents to the hyperbola x ^2 - 2y ^2 = 18 which are perpendicular to the line x - y = 0.

Find the equation of the tangent to the curve (ii) x^2 +5y^2 = 9at (2,-1)