1. **State the problem:** Find the limit $$\lim_{x \to 1} \frac{x^3 - 3x + 2}{x^3 - 4x + 3}$$.
2. **Check direct substitution:** Substitute $x=1$ into numerator and denominator:
$$1^3 - 3(1) + 2 = 1 - 3 + 2 = 0$$
$$1^3 - 4(1) + 3 = 1 - 4 + 3 = 0$$
Both numerator and denominator equal zero, so we have an indeterminate form $\frac{0}{0}$.
3. **Factor numerator and denominator:**
Numerator: $x^3 - 3x + 2$
Try to factor by finding roots:
Test $x=1$: $1 - 3 + 2 = 0$, so $(x-1)$ is a factor.
Divide numerator by $(x-1)$:
$$\frac{x^3 - 3x + 2}{x-1} = x^2 + x - 2$$
Factor $x^2 + x - 2$:
$$(x+2)(x-1)$$
So numerator factors as:
$$(x-1)(x+2)(x-1) = (x-1)^2 (x+2)$$
Denominator: $x^3 - 4x + 3$
Test $x=1$: $1 - 4 + 3 = 0$, so $(x-1)$ is a factor.
Divide denominator by $(x-1)$:
$$\frac{x^3 - 4x + 3}{x-1} = x^2 + x - 3$$
Factor $x^2 + x - 3$:
No simple integer roots, so keep as is.
Denominator factors as:
$$(x-1)(x^2 + x - 3)$$
4. **Rewrite the limit:**
$$\lim_{x \to 1} \frac{(x-1)^2 (x+2)}{(x-1)(x^2 + x - 3)}$$
5. **Cancel common factor $(x-1)$:**
$$\lim_{x \to 1} \frac{\cancel{(x-1)} (x-1) (x+2)}{\cancel{(x-1)} (x^2 + x - 3)} = \lim_{x \to 1} \frac{(x-1)(x+2)}{x^2 + x - 3}$$
6. **Evaluate the limit by direct substitution:**
Substitute $x=1$:
Numerator: $(1-1)(1+2) = 0 \times 3 = 0$
Denominator: $1^2 + 1 - 3 = 1 + 1 - 3 = -1$
7. **Final answer:**
$$\lim_{x \to 1} \frac{x^3 - 3x + 2}{x^3 - 4x + 3} = \frac{0}{-1} = 0$$
Limit Rational 5B9F29
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