For 1 consider the function
$$
f(x)=\ln(x+1)-x
$$
defined over $(-1,\infty)$, whose derivative is
$$
f'(x)=\frac{1}{x+1}-1=-\frac{x}{x+1}
$$
Can you find the absolute maximum?
For 2 consider the function
$$
g(x)=x^2-8\ln x
$$
defined over $(0,\infty)$, whose derivative is
$$
g'(x)=2x-\frac{8}{x}=\frac{2(x^2-4)}{x}
$$
Can you find the absolute minimum? What can you deduce?
For 1 consider the function $$ f(x)=\ln(x+1)-x $$ defined over $(-1,\infty)$, whose derivative is $$ f'(x)=\frac{1}{x+1}-1=-\frac{x}{x+1} $$ Can you find the absolute maximum?
For 2 consider the function $$ g(x)=x^2-8\ln x $$ defined over $(0,\infty)$, whose derivative is $$ g'(x)=2x-\frac{8}{x}=\frac{2(x^2-4)}{x} $$ Can you find the absolute minimum? What can you deduce?