Si $\sin^{-1} \left( \frac{x^2 - y^2}{x^2 + y^2} \right) = \log a$, entonces $\frac{dy}{dx}$ es igual a:

• [a.] $\frac{x}{y}$
• [b.] $\frac{y}{x^2}$
• [c.] $\frac{x^2 - y^2}{x^2 + y^2}$
• [d.] $\frac{y}{x}$