Given that the directrix is at y = 4 and the focus is at (0, -4), then the vertex is at (h, k) = (0, 0).
p is the distance between the vertex and the focus and between the vertex and the directrix = 4 and since the focus is below the directrix, p is negative, i.e. p = -4
Equation of a parabola is given by (x - h)^2 = 4p(y - k)
Therefore, the required equation is (x - 0)^2 = 4(-4)(y - 0)
x^2 = -16y
y = -1/16 x^2
Your answer is A. I have attached a photo of an explanation
Answer:
C = 8 pi cm
Step-by-step explanation:
The area of a circle is given by
A = pi r^2
16 pi = pi r^2
Divide each side by pi
16 = r^2
Taking the square root
4 = r
The circumference is
C = 2 * pi *r
C = 2* pi *(4)
C = 8 pi cm
12/84=1/7
divide the numerator and denominator of 12/84 with 12
68 degrees the reasoning would be because of corresponding angles
I hope this helps!