Question

The equation of circle A is x2 + y2 + Cx + Dy + E = 0. If the circle is moved horizontally to the left of the y-axis without changing the radius, how are the coefficients C and D affected?

C and D are unchanged.
C becomes positive, and D is unchanged.
C becomes negative, and D is unchanged.
C becomes negative, and D becomes positive.

Answer 1

I thing the most suitable is third option C becomes negative, and D is unchanged. You can check it by using special services to build graph and move it to the left and then check if I'm wrong.

Answer 2

C becomes negative, and D is unchanged.

Step-by-step explanation:

This is because the center of the circle is more easily located when the equation of the circle is given in the standar form, but still the number that are located as CD and respectivelly the values that the center of the circle will have in the graph, once you´ve divided them by 2.

So C is the position of X and D is the position of Y, so if you move the equation horizontally to the left, that´s moving only in the X axis and into the negatives, the value of D won´t change at all, while the value of C will eventually be negative.