1. **Problem:** Find the Maclaurin polynomial for $f(x) = \ln(3 + 4x)$.
2. **Formula and rules:** The Maclaurin polynomial is the Taylor polynomial centered at 0:
$$P_n(x) = \sum_{k=0}^n \frac{f^{(k)}(0)}{k!} x^k$$
We find derivatives of $f(x)$, evaluate at 0, and form the polynomial.
3. **Step 1: Evaluate $f(0)$:**
$$f(0) = \ln(3 + 4\cdot0) = \ln 3$$
4. **Step 2: First derivative:**
$$f'(x) = \frac{4}{3 + 4x}$$
Evaluate at 0:
$$f'(0) = \frac{4}{3}$$
5. **Step 3: Second derivative:**
$$f''(x) = -\frac{16}{(3 + 4x)^2}$$
Evaluate at 0:
$$f''(0) = -\frac{16}{9}$$
6. **Step 4: Third derivative:**
$$f'''(x) = \frac{128}{(3 + 4x)^3}$$
Evaluate at 0:
$$f'''(0) = \frac{128}{27}$$
7. **Step 5: Write Maclaurin polynomial up to degree 3:**
$$P_3(x) = f(0) + f'(0)x + \frac{f''(0)}{2!}x^2 + \frac{f'''(0)}{3!}x^3$$
Substitute values:
$$P_3(x) = \ln 3 + \frac{4}{3}x + \frac{-16/9}{2}x^2 + \frac{128/27}{6}x^3$$
Simplify coefficients:
$$P_3(x) = \ln 3 + \frac{4}{3}x - \frac{8}{9}x^2 + \frac{64}{81}x^3$$
**Final answer:**
$$\boxed{P_3(x) = \ln 3 + \frac{4}{3}x - \frac{8}{9}x^2 + \frac{64}{81}x^3}$$
Maclaurin Ln3Plus4X 880Dcd
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