$\lim_{x\to 0}\ \frac{3x}{x}=$ $3$ | $\lim_{x\to 0}\ \frac{x^2}{x}=$ $0$ |

$\lim_{x\to 0^+}\ \frac{x}{x^2}=$ $\infty$ | $\lim_{x\to 0^-}\ \frac{x}{x^2}=$ $-\infty$ |

$\lim_{x\to 0}\ \frac{x}{x^2}=$ does not exist | $\lim_{x\to 0^+}\ \frac{|x|}{x}=$ $1$ |

$\lim_{x\to 0^-}\ \frac{|x|}{x}=$ $-1$ | $\lim_{x\to 0}\ \frac{|x|}{x}=$ does not exist |

$\lim_{x\to 0}\ \frac{cx}{x}=$ $c$ | $\lim_{x\to 1}\ \frac{(x^2-1)}{(x-1)}=$ $2$ |

$\lim_{x\to 1}\ \frac{(\sqrt{x}-1)}{(x-1)}=$ $\frac{1}{2}$ | $\lim_{x\to a}\ \frac{(x^2-a^2)}{(x-a)}=$ $2a$ |