/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 93 In calculus we prove that the de... [FREE SOLUTION] | 91Ó°ÊÓ

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In calculus we prove that the derivative of \(f+g\) is \(f^{\prime}+g^{\prime}\) and that the derivative of \(f-g\) is \(f^{\prime}-g^{\prime} .\) It is also shown in calculus that if \(f(x)=\ln x\) then \(f^{\prime}(x)=\frac{1}{x}\) Find the derivative of \(f(x)=\ln \frac{1}{x^{2}}\)

Short Answer

Expert verified
The derivative is \( f'(x) = -\frac{2}{x} \).

Step by step solution

01

Rewrite the Logarithmic Function

First, rewrite the function using logarithmic properties. Recall that \( \ln \frac{1}{x^2} \) can be expressed as a difference: \( \ln \frac{1}{x^2} = \ln 1 - \ln x^2 \). Simplifying this using the fact that \( \ln 1 = 0 \), we have \( 0 - \ln x^2 \). Also note that \( \ln x^2 = 2 \ln x \). Hence, \( f(x) = \ln \frac{1}{x^2} = -2 \ln x \).
02

Differentiate the Function

Now, differentiate \( f(x) = -2 \ln x \) using the derivative rule for logarithmic functions. The derivative of \( \ln x \) is \( \frac{1}{x} \), so the derivative of \( -2 \ln x \) is \( -2 \times \frac{1}{x} = -\frac{2}{x} \).
03

Combine Results for Final Derivative

Combine the steps to determine that the derivative of the original function \( f(x) = \ln \frac{1}{x^2} \) is \( f'(x) = -\frac{2}{x} \). This is consistent with the logarithmic and differentiation rules applied to the function as rewritten in Step 1.

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Key Concepts

These are the key concepts you need to understand to accurately answer the question.

Logarithmic Functions
In mathematics, a logarithmic function is a mathematical function that involves a logarithm. The most common base for logarithms is either 10 (common logarithms) or the natural base, e (natural logarithms). When dealing with natural logarithms, we use the notation \( \ln x \), which stands for \( \log_e x \).
Logarithms possess unique properties that are incredibly helpful for simplifying mathematical expressions, making them crucial tools in calculus. Here are some properties:
  • Product Property: \( \ln(ab) = \ln a + \ln b \)
  • Quotient Property: \( \ln\left( \frac{a}{b} \right) = \ln a - \ln b \)
  • Power Property: \( \ln(a^c) = c \ln a \)
These properties allow us to break down complex logarithmic expressions into simpler parts, which is essential for easier differentiation and integration. In the problem, the function \( f(x) = \ln \frac{1}{x^{2}} \) was simplified to \( -2 \ln x \) using these rules, making it far easier to differentiate.
Differentiation Rules
Differentiation in calculus is all about finding the rate at which something changes. For this purpose, there are several rules that serve as shortcuts, saving us from having to resort to first principles repeatedly.
When working with logarithmic functions like \( \ln x \), the differentiation rule states that \( f'(x) = \frac{1}{x} \). This rule is derived from the basic properties of natural logarithms and the inverse nature of exponential functions.
When you want to differentiate a constant multiple of a function, such as \( -2 \ln x \), you can use the Constant Multiple Rule. It states that \( \frac{d}{dx}[c \cdot f(x)] = c \cdot f'(x) \). Therefore, the derivative of \( -2 \ln x \) with respect to \( x \) is \( -2 \cdot \frac{1}{x} \), resulting in \( -\frac{2}{x} \).
Recognizing when to apply such rules makes the process of differentiation quicker and efficient.
Calculus Concepts
Calculus is the mathematical study of continuous change, and it is fundamentally split into differential and integral calculus. Each branch tackles different types of problems and applications.
Differential calculus focuses on rates of change and slopes of curves. Its essential tool is the derivative, a measure of how a function changes as its input changes. As illustrated, finding the derivative of more complex functions often involves rewriting them using algebraic methods or function properties, like logarithmic properties. These simplifications pave the way for efficient application of differentiation rules.
Understanding the key concepts highlighted in differentiation and integration within calculus, like simplification, application of rules, and step-by-step breakdowns, aids in solving intricate mathematical problems more effectively. Through calculus, we can make sense of dynamic systems and continuous transformations that occur around us in countless fields, including physics, engineering, economics, and beyond.

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