Equation Limit Analysis
1. The problem is to analyze the equation $$\frac{x^2 + x - 6}{x - 2} = x + 3$$ and identify what is wrong with it.
2. First, factor the numerator:
$$x^2 + x - 6 = (x + 3)(x - 2)$$
3. Substitute into the fraction:
$$\frac{(x + 3)(x - 2)}{x - 2}$$
4. For all values of $x$ except $x = 2$ (which makes the denominator zero), the $x-2$ terms cancel:
$$x + 3$$
5. So the equation holds for all $x \neq 2$, but it is not defined at $x = 2$ because division by zero is undefined.
6. Therefore, the given equation is wrong if interpreted as holding for $x=2$, but correct for other $x$ values.
7. Part (b) asks why the limit equations
$$\lim_{x \to 2} \frac{x^2 + x - 6}{x - 2} = \lim_{x \to 2} (x + 3)$$
are correct.
8. When we take limits, we consider values of $x$ close to 2 but not equal to 2.
9. Since the expression simplifies to $x + 3$ for all $x \neq 2$, the limits are equal:
$$\lim_{x \to 2} \frac{x^2 + x - 6}{x - 2} = \lim_{x \to 2} (x + 3) = 2 + 3 = 5$$
10. The limit is defined even though the function is undefined at $x=2$ itself, explaining why the limit equality holds.
Final answer:
- Equation is invalid at $x=2$ as denominator is zero
- Limits are equal because expressions are equal everywhere except at $x=2$ where limit cares about approaching values.