Question

The focal distance of a point on the parabola $y^2=4x$ and above its axis, is $10$ units. Its coordinates are

• A. $(9,6)$
• B. $(25,10)$
• C. $(25,-10)$
• D. $Noneofthese$

Answer 1

The correct option is A $(9,6)$

R.E.F image

$y^2=4x$

focal distance = 10 units

comparing with $y^2=4ax$

4a=4

a=1

concept : coordinates of parabola which is open rightward $y^2=4ax(a,0)$

Focal distance = 2a

$\therefore$ coordinators of focus (1,0)

Focal distance =10

$\therefore$ x+1=10

x=9

$y^2=4\times 9$ $\therefore$ coordinators are =(9,6)

$y=\pm 6$ =(9,-6)