Sketch the graph for
(i) y = \sin^{-1} \left( \frac{2x}{1+x^2} \right)
(iii) y = \tan^{-1} \left( \frac{2x}{1-x^2} \right)
(v) y = \sin^{-1}(3x - 4x^3)
(ii) y = \cos^{-1} \left( \frac{1-x^2}{1+x^2} \right)
(iv) y = \tan^{-1} \left( \frac{3x-x^3}{1-3x^2} \right)
(vi) y = \cos^{-1}(4x^3 - 3x)