If from any point on the circle x²+y²+2gx+2fy+c=0 tangents are drawn to the circle x²+y²+2gx+2fy+csin²α+(g²+f²)cos²α=0,show that the angle between the tangents is equal to 2α.

its very easy..take the ratio of the radii....join the points from which tangents are drawn 2 d center of the circle...n let the angle b theta betn d line joinin d centers and the tangent u will find that theta equals alfa n then twice d angle will be d angle betn the tangents => 2 alfa