Leysa y=sqrt{x-1/x+3}

$$y = \sqrt { \frac { x - 1 } { x + 3 } }$$

Leystu fyrir x (complex solution)

$$x=\frac{3y^{2}+1}{1-y^{2}}$$

$$y\neq -1\text{ and }\left(y=0\text{ or }arg(y)<\pi \right)\text{ and }y\neq 1$$

Leystu fyrir y (complex solution)

$$y=\sqrt{\frac{x-1}{x+3}}$$

$$x\neq -3$$

Leystu fyrir x

$$x=\frac{3y^{2}+1}{1-y^{2}}$$

$$y\neq 1\text{ and }y\geq 0$$

Leystu fyrir y

$$y=\sqrt{\frac{x-1}{x+3}}$$

$$x\geq 1\text{ or }x<-3$$