Answer:
[tex](x-7)^2+(y-1)^2=100[/tex]
Step-by-step explanation:
1) Find the radius
We can do this by using the distance equation with the centre (7,1) and the given point (-1,-5):
[tex]d=\sqrt{(x_2-x_1)^2+(y_2-y_1)^2}[/tex] where the two points are [tex](x_1,y_1)[/tex] and [tex](x_2,y_2)[/tex]
Plug in the points (7,1) and (-1,-5)
[tex]d=\sqrt{(-1-7)^2+(-5-1)^2}\\d=\sqrt{(-8)^2+(-6)^2}\\d=\sqrt{64+36}\\d=\sqrt{100}\\d=10[/tex]
Therefore, the radius of the circle is 10 units.
2) Plug the data into the equation of a circle
Equation of a circle (when not centred at the origin):
[tex](x-h)^2+(y-k)^2=r^2[/tex] where the centre is [tex](h,k)[/tex] and r is the radius
Plug in the centre (7,1) as (h,k)
[tex](x-7)^2+(y-1)^2=r^2[/tex]
Plug in the radius 10
[tex](x-7)^2+(y-1)^2=10^2\\(x-7)^2+(y-1)^2=100[/tex]
I hope this helps!
