Question

Which equation represents a circle with the same radius as

Answer 1

Answer :

$(x+1)^2+(y-1)^2=4^2$ and $(x+1)^2+(y-1)^2=16$

Step-by-step explanation:

Given : A circle with the same radius as  the circle shown but with a center at (-1.1).

To find : Which equation represents a circle ?

Solution :

The equation of a circle with center (h,k) and radius r is given by :

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

Here, we are given (h,k)=(-1,1)

and radius r=4 units

So, equation of circle will be :

$(x-(-1))^2+(y-1)^2=4^2$

$(x+1)^2+(y-1)^2=4^2$

or $(x+1)^2+(y-1)^2=16$

Therefore, the required equations of circle are

$(x+1)^2+(y-1)^2=4^2$ and $(x+1)^2+(y-1)^2=16$