ParabolaHard
Question
The equation of lactus rectum of a parabola is x + y = 8 and the equation of the tangent at the vertex is x + y = 12, then length of L.R. is :-
Options
A.4√2
B.2√2
C.8
D.8√2
Solution
Since, the equation of latus rectum and equation of tangent both are parallel and they lie in the same side of the origin
∴ a =
= 2√2)
∴ Length of latus rectum = 4a = 4(2√2)
= 8 √2
∴ a =
= 2√2)∴ Length of latus rectum = 4a = 4(2√2)
= 8 √2
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