(1)设$y=y(x)$由 $e^{xy}=x^2 y^2 1 $确定，求 $\dfrac {dy}{dx}$.
(2)设$y=y(x)$由$\sin xy y-3x=1$确定,求$y'(0)$.
(3)设$y=y(x)$由 $e^{xy}=\sin 2x y^3$ 确定,求$y'(0)$.
$\text{A.}$ $f(x)= \dfrac {|x|}{x 1}$
$\text{B.}$ $f(x)= \sqrt { \cos x}$
$\text{C.}$ $f(x)=x \arctan \dfrac {1}{x}$
$\text{D.}$ $f(x)= \cos \sqrt {|x|}$