A circle in the xy-plane has its center at (-100,221) and a diameter of 17. Which of the following is anequation of the circle?
The formula for a circle with a center at (h,k) and aradius of r is: (x-h)2+(y-k)2=r2
The length of the radius is half of the length of thediameter.
1/2*17=8.5
Using the coordinates of the center and the length of the radius of this circle in the equationyields: (x-(-100))2+(y-221)2=8.52
In standard form, the equation of this circle is: (x+100)2+(y-221)2=72.25
解析: