Basically, the parabola has to have all points that are equidistant from the focus and the directrix, the directrix being a horizontal line, and the focus being a point given. To derive an equation from this you need to use the distance formula which I'm guessing you already know because you're already in precalc.
The gist of it is that we have a random point on the parabola (x,y), and the point (x,y) will be equidistant from both the focus and the directrix. If we use the distance formula, you get something like this:

The square root of y-(-1/2) coming from the directrix, and the righthand side of the equal sign being derived from the focus.
All you need to do is simplify now!
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Hope I helped!
Answer: symmetric or reflexive
Step-by-step explanation:
I'm not forsure but I believe that these are the two options bc the other two aren't forsure sorry dude I'm trying :0
- - Solve:
To find the volume of a sphere:

3.14≈π
Now since its telling us to use π, then we do our formula by multiplying by π.
π=3.14 (Approximate amount)
So:

So you are correct.
When Radius=9, you plug in for R. :)
Answer:
<h2>radius = 9.77 yards</h2>
Step-by-step explanation:
Since the pool is circular
Area of a circle = πr²
where
r is the radius
From the question
Area = 300 square yards
To find the radius substitute the value of the area into the above formula and solve for the radius
That's
300 = πr²
Divide both sides by π
We have

Find the square root of both sides
That's

r = 9.7720502
We have the final answer as
<h3>radius = 9.77 yards</h3>
Hope this helps you
Answer: width = 10 ft
Step-by-step explanation:
Area = length × width
Let l be length and w be width
l = w + 4 ........equation (1)
From above formula
140 = l × w. ........equation (2)
Substitute equation (1) into equation (2)
140 = (w+4) × w
w^2 + 4w= 140
w^2 + 4w - 140= 0
By factorization method
(w+14)(w-10)= 0
w=-14 or w= 10
So now width is 10 ft
From equation(1)
l=w+4
l= 10+4
l= 14 ft
Width = 10 ft and length = 14 ft