Answer:
[tex]$(x-h)^2+(y-k)^2= (r+ 40 )^2$[/tex]
Step-by-step explanation:
It is given that a meteorologist is using a Doppler radar to find out the distance of the storm as it passes using a polar grid.
The origin of the radar screen is its center.
And the distance between each ring is 10 miles from the center.
So let :
r = radius
h and k = be the coordinates of the center.
So the equation of a circle is :
[tex]$(x-h)^2+(y-k)^2= r^2 $[/tex]
Now the equation of the fourth circle when the radius changes by 10 miles is :
[tex]$(x-h)^2+(y-k)^2= (r+ 40 )^2$[/tex]