Conic Sections Question 65
Question: The equation of the tangent at a point $ P(t) $ where -t- is any parameter to the parabola $ y^{2}=4ax $ , is
[MNR 1983]
Options:
A) $ yt=x+at^{2} $
B) $ y=xt+at^{2} $
C) $ y=xt+\frac{a}{t} $
D) $ y=tx $
Show Answer
Answer:
Correct Answer: A
Solution:
Any point on $ y^{2}=4ax $ is $ (at^{2},2at) $ , then tangent is $ 2aty=2a(x+t^{2}) $
therefore $ yt=x+at^{2} $ .
BETA
