Let $f, g$ be two real functions defined by $f\left(x\right)=\sqrt{x+1}$ and $g\left(x\right)=\sqrt{9-x^2}$. Then, describe the following function: $\frac{g}{f}$.

Let $f, g$ be two real functions defined by $f\left(x\right)=\sqrt{x+1}$ and $g\left(x\right)=\sqrt{9-x^2}$. Then, describe the following function: $2f-\sqrt{5}g$.

Let $f, g$ be two real functions defined by $f\left(x\right)=\sqrt{x+1}$ and $g\left(x\right)=\sqrt{9-x^2}$. Then, describe the following function: $f^2+7f$.

Let $f, g$ be two real functions defined by $f\left(x\right)=\sqrt{x+1}$ and $g\left(x\right)=\sqrt{9-x^2}$. Then, describe the following function: $\frac{5}{g}$.

If $f\left(x\right)={\log }_{\mathrm{e}}(1-x)$ and $g\left(x\right)=\left[x\right]$, then determine the following functions: $f+g$.  Also, find $(f+g)(-1).$

If $f\left(x\right)={\log }_{\mathrm{e}}(1-x)$ and $g\left(x\right)=\left[x\right]$, then determine the following functions: $fg$.  Also, find $fg\left(0\right)$.

If $f\left(x\right)={\log }_{\mathrm{e}}(1-x)$ and $g\left(x\right)=\left[x\right]$, then determine the following functions: $\frac{f}{g}$.  Also, find $\left(\frac{f}{g}\right)\left(\frac{1}{2}\right)$.

If $f\left(x\right)={\log }_{\mathrm{e}}(1-x)$ and $g\left(x\right)=\left[x\right]$, then determine the following functions: $\frac{g}{f}$.  Also, find $\left(\frac{g}{f}\right)\left(\frac{1}{2}\right)$.