Question

Find the center-radius form of the equation of the circle with center $(4,0)$ and radius $7$

• A. ${(x-4)}^2+y^2=49$
• B. $x^2+{(y+4)}^2=7$
• C. $x^2+{(y-4)}^2=7$
• D. ${(x+4)}^2+y^2=49$

Answer 1

The correct option is A ${(x-4)}^2+y^2=49$

If $(-g,-f)$ is the center and $r$ is radius

The $(x+g{)}^2+(y+f{)}^2=r^2$ is the equation of the circle

There $C=(4,0),r=7$

$⟹(x-4{)}^2+(y-0{)}^2=7^2$

$(x–4{)}^2+(y{)}^2=49$