The domain of definition of the function $y(x)$ is given by the equation $2^x+2^y=2$, is

The domain of definition of the function $f(x)$ given by the equation $2^x+2^y=2$ is

If $\mathrm{f}(x)=\frac{x}{2-x}, \mathrm{~g}(x)=\frac{x+1}{x+2}$, then (gogof) $(x)=$

The domain of definition of $\mathrm{f}(x)=\frac{\log _2(x+3)}{x^2+3 x+2}$ is