2x21−x4\frac{2 x^{2}}{\sqrt{1-x^{4}}}1−x42x2
x1−x4\frac{x}{\sqrt{1-x^{4}}}1−x4x
2x1−x4\frac{2 x}{\sqrt{1-x^{4}}}1−x42x
−2x1−x4\frac{-2 x}{\sqrt{1-x^{4}}}1−x4−2x