C=Pi X D
Diameter is twice the radius so that would be 24 feet
C = Pi X 24
C = (22/7) X 24
C = 75.428 Feet.
draw a perpendicular line from the directrix passing through the focus, this will be the line of symmetry.
The vertex(h, k) will be located on the line half way between the focus and directrix.
The distance from the focus to the vertex is called the focal length, call it a. The then equation is
(x - h)^2 = 4a(y - k)
the equation can be manipulated to
y = 1/4a(x - h)^2 + k
hope it helps
Answer:
16an - 19an + 9an + 8b + 12b
6an + 20b
(-∞,0) ∪ (0,∞) is your answer, for any other questions please ask!