Find the radius of the circle whose equation is x^2 + y^2 = 4.

Radius of the given circle is r = 2.

Step-by-step explanation:

Given equation of the circle is .

Now we need to find the radius of the given circle .

To find that let's compare with the formula of the circle with is , where r is the radius.

We get

take square root of both sides.

Hence radius of the given circle is r = 2.

ANSWER

The radius is 2

EXPLANATION

The given equation of the circle is

.This is the same as

We campare to the equation of the circle with center at the origin.

We have

.Hence the radius of the circle is 2

the answer is d

the answer is in the first quadrant, which make the y-int positive.

since the dots are going down, therefore the correlation is negative

i hope it is right.