Question: Evaluate the limit.
lim
h\to0
\frac{\frac{1}{(h + 3)^2} - \frac{1}{9}}{h}
1. **State the problem:** We want to evaluate the limit
$$\lim_{h \to 0} \frac{\frac{1}{(h + 3)^2} - \frac{1}{9}}{h}$$
2. **Recall the formula:** This is a difference quotient form, often used to find derivatives.
3. **Rewrite the expression:**
$$\frac{\frac{1}{(h + 3)^2} - \frac{1}{9}}{h} = \frac{\frac{9 - (h + 3)^2}{9 (h + 3)^2}}{h}$$
4. **Simplify the numerator inside the fraction:**
$$(h + 3)^2 = h^2 + 6h + 9$$
So,
$$9 - (h + 3)^2 = 9 - (h^2 + 6h + 9) = -h^2 - 6h$$
5. **Substitute back:**
$$\frac{\frac{-h^2 - 6h}{9 (h + 3)^2}}{h} = \frac{-h^2 - 6h}{9 (h + 3)^2 \cdot h}$$
6. **Factor numerator:**
$$-h^2 - 6h = -h(h + 6)$$
7. **Cancel common factor $h$ in numerator and denominator:**
$$\frac{-\cancel{h}(h + 6)}{9 (h + 3)^2 \cdot \cancel{h}} = \frac{-(h + 6)}{9 (h + 3)^2}$$
8. **Evaluate the limit as $h \to 0$:**
$$\lim_{h \to 0} \frac{-(h + 6)}{9 (h + 3)^2} = \frac{-(0 + 6)}{9 (0 + 3)^2} = \frac{-6}{9 \cdot 9} = \frac{-6}{81} = -\frac{2}{27}$$
**Final answer:**
$$\boxed{-\frac{2}{27}}$$