Question
Question: The equation \(\frac{x^{2}}{1 - r}\)– \(\frac{y^{2}}{1 + r}\)= 1, r \> 1 represents...
The equation 1−rx2– 1+ry2= 1, r > 1 represents
A
An ellipse
B
A hyperbola
C
A circle
D
None of these
Answer
None of these
Explanation
Solution
1−rx2–1+ry2= 1; (r > 1)
Let r = 2 Ž (−1)x2– 3y2= 1
Ž 3x2 + y2 = –3
Ž 3x2 + y2 + 3 = 0
It is not a circle, ellipse and hyperbola.
\ none of these
Note : If (r < –1) Ž then equation is an ellipse
and if (–1 < r < 1)
Ž then equation represents a hyperbola.