Conic Sections Question 92
Question: If the parabola $ y^{2}=4ax $ passes through the point (1, -2), then the tangent at this point is
[MP PET 1998]
Options:
A) $ x+y-1=0 $
B) $ x-y-1=0 $
C) $ x+y+1=0 $
D) $ x-y+1=0 $
Show Answer
Answer:
Correct Answer: C
Solution:
$ \because $ Parabola passes through the point (1,-2), then $ 4=4a\Rightarrow a=1 $
Formula for tangent, $ yy_1=2a(x+x_1) $
therefore $ -2y=2(x+1) $
Required tangent is, $ x+y+1=0 $ .
BETA
