question_answer

The point \[(a,2a)\] is an interior point of region bounded by the parabola \[{{x}^{2}}=16y\] and the double ordinate through focus then

A) a<4     

B) 0<a<4

C) 0<a<2

D) a>4

Correct Answer: C

Solution :

[c] Parabola \[{{x}^{2}}=16y,\] axis is the y-axis, focus \[=(0,4)\] It is clear if point \[P(a,2a)\]lies interior region then ordinate \[\in (0,4)\Rightarrow 0<2a<4\Rightarrow 0<a<2\]