Which equation represents a parabola that has a focus of (0 0) and a directrix of y = 2 1. x^2 = - (y-1) 2. x^2 = -4y 3. x^2 = -y 4. x^2 = -4 (y-1)

4.

Step-by-step explanation:

Given,

Focus of parabola = (0,0)

And, directrix is, y = 2,

Thus, the parabola must be along y-axis,

We know that,

The standard form of a parabola along y-axis,

Where, focus = (h, k+p)

And, directrix, y = k-p

Thus, we can write,

h = 0, k+p = 0

k-p = 2

⇒ k+p + k-p = 0 + 2

⇒ 2k = 2 ⇒ k = 1

⇒ 1 - p = 2 ⇒ p = - 1

Hence, the equation of the parabola is,

Option 4 is correct.

the answer will be

d 25 pi/6

step-by-step explanation:

the diameter is 10 inches

the radius is 1/2 of the diameter or 5 inches

the area of the circle is

a = pi r^2

  = pi 5^2

  = 25 pi

the slice is 60 degrees of the entire circle.

60 degrees out of 360   60/360 = 1/6

the area of the slice is 1/6 of the circle

a slice = 1/6 a circle

a slice = 1/6 * 25 pi