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Question
Select the correct option from the given alternatives:
The length of latus rectum of the parabola x2 – 4x – 8y + 12 = 0 is _________
Options
4
6
8
10
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Solution
8
Explanation:
Hint: The given equation can be written as:
x2 – 4x + 4 = 8y – 12 + 4
∴ (x – 2)2 = 8(y – 1)
This is of the form X2 = 4bY, where 4b = 8
∴ l(L.R.) = 4b = 8
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