Question

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?

• A. $x^2+y^2=80$
• B. ${(x-0)}^2+{(y-0)}^2=80$
• C. $x^2+y^2=1600$
• D. $x^2+y^2=6400$

Answer 1

The correct option is D $x^2+y^2=6400$

the general equation of a circle with center at (a,b) and radius r is

$(x-a{)}^2+(y-b{)}^2=r^2$

so substituting the values we get the circle equation as

$x^2+y^2={80}^2=6400$ option D