371.

If a = 9 is a chord of contact of the hyperbola x² - y² = 9, then the equation of the tangent at one of the points of contact is 

• $\mathrm{x} + \sqrt{3}\mathrm{y} + 2 = 0$

• $3\mathrm{x} + 2\sqrt{2}\mathrm{y} - 3 = 0$

• $3\mathrm{x} - \sqrt{2}\mathrm{y} + 6 = 0$

• $\mathrm{x} - \sqrt{3}\mathrm{y} + 2 = 0$

The area (in sq units) bounded by the curves x = - 2y² and x = 1 - 3y² is

• $\frac{2}{3}$

• 1

• $\frac{4}{3}$

• $\frac{5}{3}$

A circle with centre at (2, 4) is such that the line x + y + 2 = 0 cuts a chord of length 6. The radius of the circle is

• $\sqrt{41} \mathrm{cm}$

• $\sqrt{11} \mathrm{cm}$

• $\sqrt{21} \mathrm{cm}$

• $\sqrt{31} \mathrm{cm}$

The point at which the circles x² + y² - 4x - 4y + 7 = 0 and x² + y² - 12x - 10y + 45 = 0 touch each other, is

• $\left(\frac{13}{5}, \frac{{\displaystyle 14}}{{\displaystyle 5}}\right)$

• $\left(\frac{2}{5}, \frac{{\displaystyle 5}}{{\displaystyle 6}}\right)$

• $\left(\frac{14}{5}, \frac{{\displaystyle 13}}{{\displaystyle 5}}\right)$

• $\left(\frac{12}{5}, 2 + \frac{{\displaystyle \sqrt{21}}}{{\displaystyle 5}}\right)$

The length of the common chord of the two circles x² + y² - 4y = 0 and x² + y² - 8x - 4y + 11 = 0, is

• $\frac{\sqrt{145}}{4} \mathrm{cm}$

• $\frac{\sqrt{11}}{2} \mathrm{cm}$

• $\sqrt{135} \mathrm{cm}$

• $\frac{\sqrt{135}}{4}$

The locus of the centre of the circle, which cuts the circle x² + y² - 20 + 4 = 0 orthogonally and touches the line x = 2, is

• x² = 16y

• y² = 4x

• y² = 16x

• x² = 4y

If a normal chord at a point t on the parabola y² = 4ax subtends a right angle at the vertex, then t equals to

• 1

• $\sqrt{2}$

• 2

• $\sqrt{3}$

The slopes of the focal chords of the parabola y² = 32x, which are tangents to the circle x² + y² = 4, are

• $\frac{1}{2}, - \frac{1}{2}$

• $\frac{1}{\sqrt{3}}, \frac{- 1}{\sqrt{3}}$

• $\frac{1}{\sqrt{15}}, \frac{- 1}{\sqrt{15}}$

• $\frac{2}{\sqrt{5}}, \frac{- 2}{\sqrt{5}}$

If tangents are drawn from any point on the circle x² + y² = 25 to the ellipse $\frac{{\mathrm{x}}^2}{16} + \frac{{\mathrm{y}}^2}{9} = 1$,  then the angle between the tangents is

• $\frac{2\mathrm{\pi }}{3}$

• $\frac{\mathrm{\pi }}{4}$

• $\frac{\mathrm{\pi }}{3}$

• $\frac{\mathrm{\pi }}{2}$

An ellipse passing through has $\left(4\sqrt{2}, 2\sqrt{6}\right)$ foci at (- 4, 0) and (4, 0). Then, its eccentricity

• $\sqrt{2}$

• $\frac{1}{2}$

• $\frac{1}{\sqrt{2}}$

• $\frac{1}{\sqrt{3}}$