Assertion: parabola's focus | /r/HasProperty | the line
Facets:
Source sentences:
text: Therefore, the focus is (0, 1/4a) = (0, 1/[4(-1/2)]) = (0, -1/2) and the directrix is the line y
text: dThe midpoint between the directrix and the focus falls on the parabola and is called theThe line that passes through the focus and the vertex is called the.