General solution of $\frac{dy}{dx}+\sqrt{\frac{1-y^2}{1-x^2}}=0$ is :

$sin^{-1}x+sin^{-1}y=c$ $sin^{-1}x+sin^{-1}y=c$ $\frac{sin^{-1}x}{cos^{-1}x}=c$ $sin^{-1}xcos^{-1}y=c$

$sin^{-1}x+sin^{-1}y=c$