$$\lim_{b \to 0^-}\left(\frac{b}{a}\right) = 0$$
More at b→0 from the left$$\lim_{b \to 0^+}\left(\frac{b}{a}\right) = 0$$
$$\lim_{b \to \infty}\left(\frac{b}{a}\right) = \infty \operatorname{sign}{\left(\frac{1}{a} \right)}$$
More at b→oo$$\lim_{b \to 1^-}\left(\frac{b}{a}\right) = \frac{1}{a}$$
More at b→1 from the left$$\lim_{b \to 1^+}\left(\frac{b}{a}\right) = \frac{1}{a}$$
More at b→1 from the right$$\lim_{b \to -\infty}\left(\frac{b}{a}\right) = - \infty \operatorname{sign}{\left(\frac{1}{a} \right)}$$
More at b→-oo