Question

Which equation represents the boundary circle for the region where the station can be heard?

Answer 1

Given a circle of centre (-7, -2) and a radius of 2 units,

The formula to find the equation of a cirlce is given below as,

`\begin{gathered} (x-h)^2+(y-k)^2=r^2 \\ \text{Where } \\ (h,k)=(-7,-2),r=2units \end{gathered}`

Substituting for (h, k) and r into the equation of a circle above,

`\begin{gathered} (x-(-7))^2+(y-(-2))^2=2^2_{} \\ (x+7)^2+(y+2)^2=4 \end{gathered}`

The equation of the circle is (x+7)² + (y+2)² = 4