4 If f(x) = (3x − 4)³ · (8x² + 6)*, find f'(x) using logarithmic differentiation.

Calculus: Early Transcendentals
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Author:James Stewart
Publisher:James Stewart
Chapter1: Functions And Models
Section: Chapter Questions
Problem 1RCC: (a) What is a function? What are its domain and range? (b) What is the graph of a function? (c) How...
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### Problem Statement

If \( f(x) = (3x - 4)^3 \cdot (8x^2 + 6)^4 \), find \( f'(x) \) using logarithmic differentiation.

### Instructions

To solve this problem, you will apply logarithmic differentiation, a technique that utilizes the properties of logarithms to simplify the differentiation of complex functions, especially those involving products or powers of functions.

### Steps:

1. **Take the natural logarithm of both sides:**

   Start by letting \( y = f(x) \), which means:
   \[
   y = (3x - 4)^3 \cdot (8x^2 + 6)^4
   \]
   Then take the natural logarithm:
   \[
   \ln(y) = \ln((3x - 4)^3 \cdot (8x^2 + 6)^4)
   \]

2. **Expand using logarithm properties:**

   Use the property that \(\ln(ab) = \ln(a) + \ln(b)\) and \(\ln(a^b) = b\ln(a)\):
   \[
   \ln(y) = 3\ln(3x - 4) + 4\ln(8x^2 + 6)
   \]

3. **Differentiate both sides:**

   Differentiate implicitly with respect to \(x\):
   \[
   \frac{1}{y} \frac{dy}{dx} = 3\left(\frac{1}{3x - 4}\right)(3) + 4\left(\frac{1}{8x^2 + 6}\right)(16x)
   \]

4. **Simplify the derivatives:**

   \[
   \frac{1}{y} \frac{dy}{dx} = \frac{9}{3x - 4} + \frac{64x}{8x^2 + 6}
   \]

5. **Solve for \( \frac{dy}{dx} \) (i.e., \( f'(x) \)):**

   Multiply through by \( y \) (which is \( (3x - 4)^3 \cdot (8x^2 + 6)^4 \)) to solve for \( \frac{dy}{dx} \):
   \[
   f'(x)
Transcribed Image Text:### Problem Statement If \( f(x) = (3x - 4)^3 \cdot (8x^2 + 6)^4 \), find \( f'(x) \) using logarithmic differentiation. ### Instructions To solve this problem, you will apply logarithmic differentiation, a technique that utilizes the properties of logarithms to simplify the differentiation of complex functions, especially those involving products or powers of functions. ### Steps: 1. **Take the natural logarithm of both sides:** Start by letting \( y = f(x) \), which means: \[ y = (3x - 4)^3 \cdot (8x^2 + 6)^4 \] Then take the natural logarithm: \[ \ln(y) = \ln((3x - 4)^3 \cdot (8x^2 + 6)^4) \] 2. **Expand using logarithm properties:** Use the property that \(\ln(ab) = \ln(a) + \ln(b)\) and \(\ln(a^b) = b\ln(a)\): \[ \ln(y) = 3\ln(3x - 4) + 4\ln(8x^2 + 6) \] 3. **Differentiate both sides:** Differentiate implicitly with respect to \(x\): \[ \frac{1}{y} \frac{dy}{dx} = 3\left(\frac{1}{3x - 4}\right)(3) + 4\left(\frac{1}{8x^2 + 6}\right)(16x) \] 4. **Simplify the derivatives:** \[ \frac{1}{y} \frac{dy}{dx} = \frac{9}{3x - 4} + \frac{64x}{8x^2 + 6} \] 5. **Solve for \( \frac{dy}{dx} \) (i.e., \( f'(x) \)):** Multiply through by \( y \) (which is \( (3x - 4)^3 \cdot (8x^2 + 6)^4 \)) to solve for \( \frac{dy}{dx} \): \[ f'(x)
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