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Write the equation of a circle with center (-2, 0) and area = 64 pi

2 Answers

5 votes

Hello!

The answer is:

The equation of the given circle is:


(x+2)^(2) +(y)^(2)=64

Why?

The equation of a circle is given by the following equation:


(x-h)^(2) +(y-k)^(2)=r^(2)

We are given the center point (-2,0) and the area of the circle.

The area of a circle is given by the formula:


A=\pi*r^(2)\\64\pi=\pi*r^(2)\\64=r^(2)


A=\pi*r^(2)\\64\pi=\pi*r^(2)\\64=r^(2)\\√(64)=r\\8=r\\r=8

So, the radius of the circle is 8 units.

Therefore,

We are given a circle where:


h=x=-2\\k=y=0\\r=8

Then, substituting into the circle equation, we have:


(x-(-2))^(2) +(y-0)^(2)=(8)^


(x+2)^(2) +(y)^(2)=64

Hence, the simplified equation of the circle is:


(x+2)^(2) +(y)^(2)=64

Have a nice day!

User Eman
by
5.2k points
2 votes

Answer:

The required equation in standard form is
(x+2)^2+y^2=64

Explanation:

The equation of a circle with center (h,k) an radius, r units is given by the formula;


(x-h)^2+(y-k)^2=r^2

The given circle has center (-2,0) and radius squared can be calculated from the given area, which is
64\pi


\pi r^2=64\pi


\implies r^2=64

We substitute these values into the formula to obtain;


(x--2)^2+(y-0)^2=64

We simplify to get;


(x+2)^2+y^2=64