Limits rules at infinity
Algebraic functions
$\displaystyle \large \lim_{x\,\to\,\pm\infty}{\normalsize \dfrac{1}{x}}$ $\,=\,$ $0$
Exponential functions
$\displaystyle \large \lim_{x\,\to\,+\infty}{\normalsize e^x}$ $\,=\,$ $\infty$
$\displaystyle \large \lim_{x\,\to\,-\infty}{\normalsize e^x}$ $\,=\,$ $0$
$\displaystyle \large \lim_{x\,\to\,\pm\infty}{\normalsize \bigg(1+\dfrac{1}{\displaystyle x}\bigg)^x}$ $\,=\,$ $e$
Trigonometric functions
$\displaystyle \large \lim_{x\,\to\,\pm \infty}{\normalsize \dfrac{\sin{x}}{x}}$ $\,=\,$ $0$
