Derive the equation of the parabola with a focus at (2, 4) and a directrix of y = 8.

In this problem, given the focus at (2,4) and directrix at y = 8. then it is implied that the parabola is facing downwards. The vertex hence is at the middle of the focus and the directrix, hence at (2, 6). The general formula of the parabola is y-k = -4a  ( x-h)^2. Substituting, y -6 = -1/8 *(x-2)^2. Answer is A.

answer

explanation

the area of a circle is calculated using the formula

or

we can use any of the above formulae to calculate the required. preferably, let us use the latter since the diameter is

we substitute the diameter into the formula to get:

this is the exact value for the area of the circle.

the correct answer is a

step-by-step explanation:

options