Limit of an indeterminated form?

20 Views Asked by At

I want to find:

$$\lim_{t\to\infty}X_{t}$$

where:

$$X_{t} = \frac{A_{t}^{a}}{B_{t}}$$

I know that:

$$\lim_{t\to\infty}A_{t}=0$$

and

$$\lim_{t\to\infty}B_{t}=0$$

Can I say with certainty that:

$$\lim_{t\to\infty}X_{t}=\frac{0^{a}}{0} = \left\{\begin{array}{l l} 0 & \text{if $a > 1$}\\ 1 & \text{if $a=1$}\\ \infty & \text{if $a<1$} \end{array} \right.$$

This is, can I compare dominance of expressions?

Note that I don't have closed-form expressions for $A(t)$ and $B(t)$ so I cannot do L'Hopital here. I do know their limit though, as given above.