Conic Sections Question 346
Question: If the line $ y=2x+c $ be a tangent to the ellipse $ \frac{x^{2}}{8}+\frac{y^{2}}{4}=1 $ , then $ c= $
[MNR 1979; DCE 2000]
Options:
A) $ \pm 4 $
B) $ \pm 6 $
C) $ \pm 1 $
D) $ \pm 8 $
Show Answer
Answer:
Correct Answer: B
Solution:
$ c=\pm \sqrt{b^{2}+a^{2}m^{2}}=\pm \sqrt{4+8.4}=\pm 6 $ .
BETA
