sat suite question viewer
x2+58x+y2=0
In the xy-plane, the graph of the given equation is a circle. What are the coordinates (x,y) of the center of the circle?
Explanation
Choice D is correct. It’s given that in the xy-plane, the graph of x2+58x+y2=0 is a circle. The equation of a circle in the xy-plane can be written as (x−h)2+(y−k)2=r2, where the coordinates of the center of the circle are (h,k) and the radius of the circle is r. By completing the square, the equation x2+58x+y2=0 can be rewritten as (x2+58x+(582)2)+y2=0+(582)2, or (x2+58x+841)+y2=841. This equation is equivalent to (x+29)2+y2=841, or (x−(−29))2+(y−0)2=841. Therefore, h is −29 and k is 0, and the coordinates (x,y) of the center of the circle are (−29,0).
Choice A is incorrect and may result from conceptual or calculation errors.
Choice B is incorrect and may result from conceptual or calculation errors.
Choice C is incorrect and may result from conceptual or calculation errors.