Question:
Find the coordinates of a point on the parabola y2 = 8x whose focal distance is 4.
Solution:
We know that equation of an ellipse is y2 = 4ax,
Also we have length of latus rectum = 4a
Now by comparing the above two equations,
4a = 8
Therefore
a = 2
y2 = 8 × 2 = 16
y = ± 4 and x = 2
Hence the co – ordinates are (2, 4) and (2, -4).