4.13 (i) Show that the locus of the points P(x, y) obeying the equation x² + y² + 2gx + 2fy + c = 0 represents a circle. (ii) Express the

coordinates of the center and the radius. Use the following equations of circles to find the centers and radii. x² + y² + 8x - 4y + 11 = 0 x+y²-10x-6y + 9 = 0 225x² + 225y² + 90x - 300y + 280 jeol. 0000 ↓i(0) jac FIGURE MA-6 A series RLC circuit for Problem 4.12.