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

4x4 - 48x2 + 80 = 0
 x1 = 3.16  x2 = -3.16
x3 = 1.41  x4 = -1.41		-9x4 + 180x2 - 900 = 0
 x1 = 3.16  x2 = -3.16
x3 = 3.16  x4 = -3.16
4.5x4 + 31.5x2 - 81 = 0
 x1 = ◊  x2 = ◊
x3 = 1.41  x4 = -1.41		-10x4 + 90x2 = 0
 x1 = 3  x2 = -3
x3 = 0  x4 = 0
-3.5x4 - 35x2 - 84 = 0
 x1 = ◊  x2 = ◊
x3 = ◊  x4 = ◊		-2.5x4 - 10x2 + 52.5 = 0
 x1 = 1.73  x2 = -1.73
x3 = ◊  x4 = ◊
-2x4 - 30x2 - 100 = 0
 x1 = ◊  x2 = ◊
x3 = ◊  x4 = ◊		10x4 + 130x2 + 300 = 0
 x1 = ◊  x2 = ◊
x3 = ◊  x4 = ◊
-7.5x4 - 67.5x2 - 135 = 0
 x1 = ◊  x2 = ◊
x3 = ◊  x4 = ◊		-0.5x4 - 9x2 - 40.5 = 0
 x1 = ◊  x2 = ◊
x3 = ◊  x4 = ◊
-7x4 - 49x2 - 42 = 0
 x1 = ◊  x2 = ◊
x3 = ◊  x4 = ◊		-1.5x4 - 4.5x2 + 60 = 0
 x1 = 2.24  x2 = -2.24
x3 = ◊  x4 = ◊
9.5x4 + 19x2 - 332.5 = 0
 x1 = 2.24  x2 = -2.24
x3 = ◊  x4 = ◊		-5.5x4 + 5.5x2 + 165 = 0
 x1 = ◊  x2 = ◊
x3 = 2.45  x4 = -2.45
-3x4 + 18x2 + 21 = 0
 x1 = 2.65  x2 = -2.65
x3 = ◊  x4 = ◊		-10x4 + 180x2 - 800 = 0
 x1 = 3.16  x2 = -3.16
x3 = 2.83  x4 = -2.83
-4x4 + 64 = 0
 x1 = ◊  x2 = ◊
x3 = 2  x4 = -2		-8x4 - 40x2 = 0
 x1 = 0  x2 = 0
x3 = ◊  x4 = ◊
-9x4 - 162x2 - 729 = 0
 x1 = ◊  x2 = ◊
x3 = ◊  x4 = ◊		-x4 - 2x2 = 0
 x1 = ◊  x2 = ◊
x3 = 0  x4 = 0