MCQ
The equation $\frac{{{x^2}}}{{1 - r}} - \frac{{{y^2}}}{{1 + r}} = 1,\;r > 1$ represents
  • A
    An ellipse
  • B
    A hyperbola
  • C
    A circle
  • An imaginary ellipse

Answer

Correct option: D.
An imaginary ellipse
d
(d) $\frac{{{x^2}}}{{1 - r}} - \frac{{{y^2}}}{{1 + r}} = 1$, where $r > 1$

or $\frac{{{x^2}}}{{ - p}} - \frac{{{y^2}}}{q} = 1,\,\,\,1 - r = - p$ $(say)$ or $\frac{{{x^2}}}{{ - p}} + \frac{{{y^2}}}{{ - q}} = 1$ i.e., imaginary ellipse with imaginary major and minor axes.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

Equation of horizontal line above x-axis at 5 units from x-axis is:
A box $'A'$ contanis $2$ white, $3$ red and $2$ black balls. Another box $'B'$ contains $4$ white, $2$ red and $3$ black balls. If two balls are drawn at random, without replacement, from a randomly selected box and one ball turns out to be white while the other ball turns out to be red, then the probability that both balls are drawn from box $'B'$ is
Choose the correct answer. Let a, b, c, d, e be the observations with mean m and standard deviation s. The standard deviation of the observations a + k, b + k, c + k, d + k, e + k is:
If the point on the curve $y^{2}=6 x$, nearest to the point $\left(3, \frac{3}{2}\right)$ is $(\alpha, \beta)$, then $2(\alpha+\beta)$ is equal to $.....$
The centre of a regular polygon of $n$ sides is located at the point $z = 0$ and one of its vertex ${z_1}$ is known. If ${z_2}$ be the vertex adjacent to ${z_1}$, then ${z_2}$ is equal to
Let $r_1, r_2, r_3$ be roots of equation $x^3 -2x^2 + 4x + 5074 = 0$, then the value of $(r_1 + 2)(r_2 + 2)(r_3 + 2)$ is
If $\tan \theta = \frac{{x\,\sin \,\phi }}{{1 - x\,\cos \,\phi }}$ and $\tan \,\phi = \frac{{y\sin \,\theta }}{{1 - y\,\cos \,\theta }}$, then $\frac{x}{y} = $
If $\sin x+\sin y=\frac{7}{5}$ and $\cos x+\cos y=\frac{1}{5}$, then $\sin (x+y)$ equals
If the plane 7x + 11y + 13z = 3003 meets the axes in A, B, C then the centroid of $\Delta\text{ABC}$ is:
If slope of a line is 4 and y-intercept made by the line is 2 then the equation of line will be: