Q. A circle in the xy-plane has the equation x2+y2−14y−51=0. What is the center of the circle?Choose 1 answer:(A) (51,14)(B) (7,10)(C) (0,0)(D) (0,7)
Complete the square: First, we need to complete the square for the y terms.x2+y2−14y=51To complete the square, take half of the coefficient of y, square it, and add it to both sides.Half of −14 is −7, and (−7)2=49.So, we add 49 to both sides.x2+y2−14y+49=51+49x2+(y−7)2=100
Circle equation form: Now, we have the equation of the circle in the form (x−h)2+(y−k)2=r2, where (h,k) is the center and r is the radius.From the equation x2+(y−7)2=100, we can see that h=0 and k=7.
Center of the circle: So, the center of the circle is (h,k)=(0,7).
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