What are the coordinates of the focus and the equation of the directrix?

Mathematics

1 answer:

g100num [7]3 years ago

8 0

The answer is C. focus: (–4,0); directrix: x = 4

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Find the area of a slice of a 16 inch pizza that is cut into 8 slices

VARVARA [1.3K]

Answer:

≈ 25 in²

Step-by-step explanation:

The general formula for the area of a circle is:

A=πr²

A = (3.14)(8²)

Since the size of the pizza is 16 inches across, the radius is half of that, or 16÷2 = 8 inches.

A ≈ 201 in²

Since there 8 slices of pizza, you can take the total area and divide by 8:

201 ÷ 8 ≈ 25 in²

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3 years ago

Mike withdrew $32 from his bank account. The transaction slip said his balance was $289.14. What was his previous balance?

Temka [501]

His previous balance was $321.14
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4 0

3 years ago

NO LINKS!!!! Find the equation of the circle below

inysia [295]

Answer:

$(x+3)^2+(y-2)^2=9$

Step-by-step explanation:

Equation of a circle

$(x-a)^2+(y-b)^2=r^2$

where:

(a, b) is the center
r is the radius

From inspection of the diagram, the center of the circle appears to be at point (-3, 2), although this is not very clear. Therefore, a = -3 and b = 2.

Substitute these values into the general form of the equation of a circle:

$\implies (x-(-3))^2+(y-2)^2=r^2$

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Again, from inspection of the diagram, the maximum vertical point of the circle appears to be at y = 5. Therefore, to calculate the radius, subtract the y-value of the center point from the y-value of the maximum vertical point:

⇒ radius (r) = 5 - 2 = 3

Substitute the found value of r into the equation:

$\implies (x+3)^2+(y-2)^2=3^2$