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NCERT Class XI Mathematics - Conic Sections - Solutions
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Question : 60 of 71
Marks:
+1,
-0
Foci (±4, 0), the latus rectum is of length 12.
Solution:
Here foci are (±4, 0) which lie on x-axis. So the equation of the hyperbola in standard form is = 1. Now Foci are (±4, 0) ⇒ c = 4. Length of latus rectum is = 12 ⇒ = 6a We know that = ∴ = + 6a ⇒ + 6a – 16 = 0 ⇒ (a + 8)(a – 2) = 0 ⇒ a = 2 (Since a = – 8 is not possible) ∴ = 4 ⇒ = 6 × 2 = 12 Thus, required equation of hyperbola is = 1.
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