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3 years ago

What is the equation of the parabola with a directrix at y = 4 and focus (0, -4).

1 answer:

3 0

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

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The scale of a certain map is 4/5 inch = 16 miles. A square park is represneted on the map by a square with side length 5/8 inch

lions [1.4K]

Answer:

The area of this park is 130.60 square miles.

Step-by-step explanation:

Given : The scale of a certain map is $\frac{4}{5}$ inch = 16 miles. A square park is represented on the map by a square with side length $\frac{5}{8}$ inch.

To find : What is the actual area of this park?

Solution :

The scale of a certain map is $\frac{4}{5}$ inch = 16 miles.

Let the side length of $\frac{5}{8}$ inch = x miles.

So, $\dfrac{\frac{4}{5}}{\frac{5}{8}}=\dfrac{16}{x}$

$\dfrac{4\times 8}{5\times5}=\dfrac{16}{x}$

$\dfrac{32}{25}=\dfrac{16}{x}$

$x=\dfrac{16\times 25}{35}$

$x=11.428$

The side length of a square is 11.428 miles.

The area of the square is $A=s^2$ .

$A=(11.42)^2$

$A=130.599\ miles^2$

To nearest hundredth,

The area of this park is 130.60 square miles.

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3 years ago

Help me with this problem plz

katrin [286]

4.43

To find the mean (average) # of sick days taken, you add all the numbers, then divide by the number of employees.

31 ÷ 7 = 4.4285714286 or aprox. 4.43

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4 years ago

The amount of money, in dollars, Sarah has in her savings account is modeled as a function of time in months. This function is r

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Answer:

330.60.330.60.330.60.

Step-by-step explanation:

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A yard of fabric costs 22.99 how much will 2 feet costs

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3 years ago

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Hi!! if you dont want to use points google graph calculator. There is a good website called Graphing calculator-symbolab Its really helpful. Good Luck!!
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