The equation of the normal to the circle x2+y2=5 at the point (1,2) is
Find the equation of the circle passing the point (1, 2) and touching the line 2x + y - 1 = 0 at the point (1, -1).
Find the equation of chord centered at the point (1, 2) in the circle x2 + y2 = 9.
Equation of the diameter of the circle x2+y2−2x+4y=0 which passes through the origin is