NCERT Class XI Mathematics - Conic Sections - Solutions
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Question : 55
Total: 71
Vertices (0, ±5), foci (0, ±8)
Solution:
Vertices are (0, ±5) which lie on y-axis.
So the equation of hyperbola in standard form is
−
= 1
Now vertices are (0, ±5) ⇒ a = 5; Foci are (0, ±8) ⇒ ae = 8
Now, ae = 8 ⇒ e =
⇒ e =
We know that b =a √ e 2 − 1 ⇒ b = 5 √
− 1 = 5
= √ 39
Thus required equation of parabola is
−
= 1 ⇒
−
= 1.
So the equation of hyperbola in standard form is
Now vertices are (0, ±5) ⇒ a = 5; Foci are (0, ±8) ⇒ ae = 8
Now, ae = 8 ⇒ e =
We know that b =
Thus required equation of parabola is
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