Aradio telescope has a parabolic surface, as shown below. ( it is a parabola opening up with vertex at the origin) the height of the parabola from top to bottom is 1 meter and its width from left to right is 8 meters. if the telescope is 1 m deep and 8 m wide, how far is the focus from the vertex?

1 m
2 m
4 m
16 m

There are several information's that are already given in the question. Based on those given information's, one can say that the origin of the parabola is opening up with the vertex of the parabola. We already know that the formula for a parabola with vertex at the origin is x^2 = 4py, where "p" is the focus. Now putting the dimensions given in the question in the formula, we get 0.25 as the correct result. I hope the answer has come to your help. Or heres a more define one:
Basing on the description, a parabola opening up with vertex at origin, the formula with vertex at origin is used, x^2 = 4py. p is the focus and so with the dimensions given, we obtain a 0.25 and that is the distance of the focus to the vertex.

Hope i can you!