If $x = \theta - \frac{1}{\theta}$ and $y = \theta + \frac{1}{\theta}$, then $\frac{dy}{dx}$ is equal to :

Question

( A ) $\frac{x}{y}$
( B ) $-\frac{x}{y}$
( C ) $-\frac{y}{x}$
( D ) $\frac{y}{x}$