Use a shown antiderivative inside integration by parts

(i) Show that $\displaystyle\int\dfrac{x}{\sqrt{1-x^2}}\,dx=-\sqrt{1-x^2}+c$, where $c$ is an arbitrary constant.2 marks

(ii) Hence find $\displaystyle\int(\sin^{-1}x)\dfrac{x}{\sqrt{1-x^2}}\,dx$.4 marks