If all the points on the curve C: x2 + Y2 + 2ax-4ay + 5a2-4 = 0 are in the second quadrant, then the value range of a is______ .

If all the points on the curve C: x2 + Y2 + 2ax-4ay + 5a2-4 = 0 are in the second quadrant, then the value range of a is______ .


Given that the equation of circle is x2 + Y2 + 2ax-4ay + 5a2-4 = 0, the standard equation of circle is: (x + a) 2 + (y-2a) 2 = 4, so the center of circle is (- A, 2a), and the radius of circle is 2. If all the points on the curve C: x2 + Y2 + 2ax-4ay + 5a2-4 = 0 are in the second quadrant, then a > 0, and | - a | > 2, the value of a > 2 is obtained