Conic Sections Question 434
Question: The latus rectum of a parabola whose directrix is $ x+y-2=0 $ and focus is (3, - 4), is
Options:
A) $ -3\sqrt{2} $
B) $ 3\sqrt{2} $
C) $ -3/\sqrt{2} $
D) $ 3/\sqrt{2} $
Show Answer
Answer:
Correct Answer: B
Solution:
Distance between focus and directrix is $ =| \frac{3-4-2}{\sqrt{2}} |=\frac{\pm 3}{\sqrt{2}} $
Hence latus rectum $ =3\sqrt{2} $ (Since latus rectum is two times the distance between focus and directrix).