Circles Test 9...

An ambulance company provides services within an 80 mile radius of their headquarters If this service area is represented graphically with the headquarters located at the coordinates (0, 0) what is the equation that represents the service area?

The radius of the circle $$x^{2} + y^{2} + 4x + 6y + 13 = 0$$ is

Graph the circle
$${ \left( x-3 \right)  }^{ 2 }+{ \left( y+4 \right)  }^{ 2 }=4$$

The equation of a circle which has a tangent $$3x+4y=6$$ and two normals given by $$(x-1)(y-2)=0$$ is

Find the equation of the circle with center on x + y = 4 and 5x + 2y + 1 = 0 and having a radius of 3

Find the equation of k for which the equation $$\displaystyle x^{2}+y^{2}+4x-2y-k=0$$ represents a point circle

The radius of the circle passing through the point $$(6, 2)$$ and two of whose diameters are $$\displaystyle x+y=6$$ and $$\displaystyle x+2y=4$$ is:

The equation of the circle whose centre and radius are $$\left( 1,-1 \right) $$ and $$4$$ respectively, is

Write the equation of the circle with center at $$(0,0)$$ and a radius of $$6$$

Find the equation of a circle with center $$(2,0)$$ and passing through point $$\left( 3,\sqrt { 3 }  \right) $$.