NCERT Class XI Mathematics - Conic Sections - Solutions
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Question : 50
Total: 71
Solution:
Given equation of hyperbola is 9 y 2 – 4 x 2 = 36
i.e.,
−
= 1 ⇒
−
= 1 , which is of the form
−
= 1.
The foci and vertices of the hyperbola lie on y-axis.
Now,a 2 = 4 ⇒ a = 2 and b 2 = 9 ⇒ b = 3
Also,c 2 = a 2 + b 2 = 4 + 9 = 13 ⇒ c = √ 13
∴ Coordinates of foci are (0, ± c) i.e. (0, ±√ 13 )
∴ Coordinates of vertices are (0, ±a) i.e. (0, ±2)
Eccentricity (e) =
=
Length of latus rectum =
=
= 9.
i.e.,
The foci and vertices of the hyperbola lie on y-axis.
Now,
Also,
∴ Coordinates of foci are (0, ± c) i.e. (0, ±
∴ Coordinates of vertices are (0, ±a) i.e. (0, ±2)
Eccentricity (e) =
Length of latus rectum =
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