Limit Ln Over Square 69Ada9
1. **State the problem:** Find the limits of the function $$f(x) = \frac{\ln(x)}{(x-1)^2}$$ as $$x \to +\infty$$, $$x \to 0^+$$, $$x \to 1^+$$, and $$x \to 1^-$$.
2. **Recall important facts:**
- The natural logarithm function $$\ln(x)$$ grows slowly to infinity as $$x \to +\infty$$.
- The denominator $$(x-1)^2$$ is always positive except at $$x=1$$ where it is zero.
- Limits involving division by zero may tend to infinity or negative infinity depending on numerator behavior.
3. **Limit as $$x \to +\infty$$:**
- Numerator: $$\ln(x) \to +\infty$$ slowly.
- Denominator: $$(x-1)^2 \to +\infty$$ faster (quadratic growth).
- So, $$\lim_{x \to +\infty} \frac{\ln(x)}{(x-1)^2} = \frac{+\infty}{+\infty}$$, but denominator dominates.
- Using L'Hôpital's Rule:
$$\lim_{x \to +\infty} \frac{\ln(x)}{(x-1)^2} = \lim_{x \to +\infty} \frac{\frac{1}{x}}{2(x-1)} = \lim_{x \to +\infty} \frac{1}{2x(x-1)} = 0$$.
4. **Limit as $$x \to 0^+$$:**
- Numerator: $$\ln(x) \to -\infty$$.
- Denominator: $$(x-1)^2 \to 1$$ (since $$x \to 0$$, $$x-1 \to -1$$).
- So, $$\lim_{x \to 0^+} \frac{\ln(x)}{(x-1)^2} = \frac{-\infty}{1} = -\infty$$.
5. **Limit as $$x \to 1^+$$:**
- Numerator: $$\ln(1) = 0$$.
- Denominator: $$(x-1)^2 \to 0^+$$.
- The form is $$\frac{0}{0}$$, so use L'Hôpital's Rule:
$$\lim_{x \to 1^+} \frac{\ln(x)}{(x-1)^2} = \lim_{x \to 1^+} \frac{\frac{1}{x}}{2(x-1)} = \lim_{x \to 1^+} \frac{1}{2x(x-1)}$$.
- As $$x \to 1^+$$, denominator $$2x(x-1) \to 0^+$$, so the limit tends to $$+\infty$$.
6. **Limit as $$x \to 1^-$$:**
- Similar to above, numerator $$\to 0$$, denominator $$\to 0^+$$.
- Using L'Hôpital's Rule again:
$$\lim_{x \to 1^-} \frac{\ln(x)}{(x-1)^2} = \lim_{x \to 1^-} \frac{1/x}{2(x-1)} = \lim_{x \to 1^-} \frac{1}{2x(x-1)}$$.
- As $$x \to 1^-$$, denominator $$2x(x-1) \to 0^-$$, so the limit tends to $$-\infty$$.
**Final answers:**
$$\lim_{x \to +\infty} \frac{\ln(x)}{(x-1)^2} = 0$$
$$\lim_{x \to 0^+} \frac{\ln(x)}{(x-1)^2} = -\infty$$
$$\lim_{x \to 1^+} \frac{\ln(x)}{(x-1)^2} = +\infty$$
$$\lim_{x \to 1^-} \frac{\ln(x)}{(x-1)^2} = -\infty$$