How to find the diameter of a circle using the circumference?

i'm not sure i quite understand, could you provide more information?

the formula for the equation of a circle is (x – h)2+ (y – k)2 = r2, where (h, k) represents the coordinates of the center of the circle, and r represents the radius of the circle. if a circle is tangent to the x-axis at (3,0), this means it touches the x-axis at that point.

i believe that the answer is

b. y-1=-2(x-4)

hope this !

for future students the answer is b

hope i

-lavira: )