Question

earthquakes Earthquakes release seismic waves that occur in concentric circles from the epicenter of the earthquake. Suppose a seismograph station determines the epicenter of an earthquake is located 9 kilometers from the station. If the epicenter is located at the origin, write the equation for the circular wave that passes through the station.

Answer 1

So you want the equation of a circle centered at the origin of radius 9.

Answer 2

standard equation of a circle
\[(x-h)^{2} + (y-k)^{2}=r ^{2}\]

Answer 3

with (h,k) as the center
but in this case, we can make the center (0,0)

Answer 4

...and r is the radius

Answer 5

^^ beat me to it!