Löse die folgenden biquadratischen Gleichungen ax4 + bx2 + c = 0

-2x4 + 8x2 = 0
 x1 = 2  x2 = -2
x3 = 0  x4 = 0		-1.5x4 - 6x2 + 48 = 0
 x1 = ◊  x2 = ◊
x3 = 2  x4 = -2
-2.5x4 + 20x2 + 22.5 = 0
 x1 = ◊  x2 = ◊
x3 = 3  x4 = -3		3.5x4 + 31.5x2 + 28 = 0
 x1 = ◊  x2 = ◊
x3 = ◊  x4 = ◊
8.5x4 - 93.5x2 + 255 = 0
 x1 = 2.45  x2 = -2.45
x3 = 2.24  x4 = -2.24		8x4 - 24x2 - 32 = 0
 x1 = 2  x2 = -2
x3 = ◊  x4 = ◊
-1.5x4 + 16.5x2 - 15 = 0
 x1 = 1  x2 = -1
x3 = 3.16  x4 = -3.16		9x4 - 45x2 + 54 = 0
 x1 = 1.41  x2 = -1.41
x3 = 1.73  x4 = -1.73
-9x4 - 27x2 + 36 = 0
 x1 = ◊  x2 = ◊
x3 = 1  x4 = -1		-5x4 + 10x2 + 15 = 0
 x1 = 1.73  x2 = -1.73
x3 = ◊  x4 = ◊
2x4 + 28x2 + 90 = 0
 x1 = ◊  x2 = ◊
x3 = ◊  x4 = ◊		5.5x4 + 11x2 - 44 = 0
 x1 = 1.41  x2 = -1.41
x3 = ◊  x4 = ◊
9x4 - 27x2 - 162 = 0
 x1 = ◊  x2 = ◊
x3 = 2.45  x4 = -2.45		5x4 - 5x2 - 450 = 0
 x1 = 3.16  x2 = -3.16
x3 = ◊  x4 = ◊
1.5x4 - 1.5x2 - 84 = 0
 x1 = 2.83  x2 = -2.83
x3 = ◊  x4 = ◊		-2.5x4 + 2.5x2 + 105 = 0
 x1 = 2.65  x2 = -2.65
x3 = ◊  x4 = ◊
-2x4 - 4x2 + 96 = 0
 x1 = ◊  x2 = ◊
x3 = 2.45  x4 = -2.45		-5x4 - 5x2 + 10 = 0
 x1 = 1  x2 = -1
x3 = ◊  x4 = ◊
-5.5x4 + 33x2 - 49.5 = 0
 x1 = 1.73  x2 = -1.73
x3 = 1.73  x4 = -1.73		-4.5x4 + 27x2 = 0
 x1 = 2.45  x2 = -2.45
x3 = 0  x4 = 0