Answer
See solution
Work Step by Step
In part b) we got that when $x\rightarrow +\infty$, $f(x)/g(x)\rightarrow 1$.
Assume that when $x\rightarrow +\infty$ $f(x)\rightarrow +\infty$ and $g(x)\rightarrow -\infty$. Then $f(x)/g(x)$ would approach a negative value, which is false as we got that $f(x)/g(x)$ approaches a positive value.
The same goes if we assume that when $x\rightarrow +\infty$ $f(x)\rightarrow -\infty$ and $g(x)\rightarrow +\infty$.
Therefore the functions $f$ and $g$ have the same end behavior as $x\rightarrow +\infty$.
