Let point (x, y) be any point on the graph, than the distance between (x, y) and the focus (3, 6) is sqrt((x - 3)^2 + (y - 6)^2) and the distance between (x, y) and the directrix, y = 4 is |y - 4|
Thus sqrt((x - 3)^2 + (y - 6)^2) = |y - 4|
(x - 3)^2 + (y - 6)^2 = (y - 4)^2
x^2 - 6x + 9 + y^2 - 12y + 36 = y^2 - 8y + 16
x^2 - 6x + 29 = -8y + 12y = 4y
(x - 3)^2 + 20 = 4y
y = 1/4(x - 3)^2 + 5
Required answer is f(x) = one fourth (x - 3)^2 + 5
I don't know, this is tricky
A standard deck of cards has 52 cards. Half of the deck has red cards and half has black cards. So the first probability would be 26/52, or 1/2 (simplified, it's half the deck).
Then you put the card back and choose a 3. There are 4 cards with the number 3 in the deck. So it's 4/52.
Then you multiply both the probabilities
26/52 x 4/52 =

= 1/26