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Use logarithmic differentiation to find the derivative of \(y\) with respect to the given independent variable. $$y=\sqrt{\frac{(x+1)^{10}}{(2 x+1)^{5}}}$$

Short Answer

Expert verified
\( \frac{dy}{dx} = 5 \cdot (x+1)^4 (2x+1)^{-\frac{7}{2}} \).

Step by step solution

01

Simplify the Expression

Given the function, \( y = \sqrt{\frac{(x+1)^{10}}{(2x+1)^{5}}} \). First, simplify the expression under the square root. Rewrite it as a single exponential term: \( y = \left( \frac{(x+1)^{10}}{(2x+1)^{5}} \right)^{\frac{1}{2}} \). This simplifies to \( y = (x+1)^5 (2x+1)^{-\frac{5}{2}} \).
02

Take the Logarithm of the Expression

To use logarithmic differentiation, take the natural logarithm of both sides. This gives: \( \ln(y) = \ln((x+1)^{5}) + \ln((2x+1)^{-\frac{5}{2}}) \). Simplify using logarithm properties to \( \ln(y) = 5 \ln(x+1) - \frac{5}{2} \ln(2x+1) \).
03

Differentiate Both Sides with Respect to x

Differentiate both sides of the equation with respect to \(x\). On the left side, you get \( \frac{1}{y} \frac{dy}{dx} \). On the right side, differentiate using the chain rule: \( 5 \frac{1}{x+1} \) for the first term and \(- \frac{5}{2} \frac{1}{2x+1} \cdot 2 \) for the second term. This results in: \( \frac{dy}{dx} = y \left( \frac{5}{x+1} - \frac{5}{2x+1} \right) \).
04

Substitute y Back in Terms of x

Substitute back \( y = (x+1)^5 (2x+1)^{-\frac{5}{2}} \) into the expression for \( \frac{dy}{dx} \). This gives \( \frac{dy}{dx} = (x+1)^5 (2x+1)^{-\frac{5}{2}} \cdot \left( \frac{5}{x+1} - \frac{5}{2x+1} \right) \).
05

Simplify the Derivative Expression

Simplify the expression from Step 4 by factoring and combining terms. Factoring \(5\) from the parentheses, we get \( \frac{dy}{dx} = 5 \cdot (x+1)^4 (2x+1)^{-\frac{7}{2}} (2x - \frac{x+1}{2x+1}) \). After algebraic simplification, this leads to the final derivative form.

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Key Concepts

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

Derivative Calculation
Derivative calculation is the process of finding how a function changes as its input changes. This is typically done using differentiation, which gives us the rate of change of the function. When dealing with complicated functions, direct application of differentiation rules may not be straightforward.

For the function given in the original exercise, we have to deal with a complex fraction raised to an exponent. Solving such derivatives requires additional techniques such as logarithmic differentiation. In this case, logarithmic differentiation simplifies the process by allowing us to take the natural logarithm of both sides of the equation, making it easier to differentiate.

In summary, the goal is to find the function's derivative, and logarithmic differentiation serves as an effective tool to simplify this process and handle functions that would otherwise be challenging to differentiate directly.
Chain Rule
The chain rule is an essential technique in calculus for differentiating compositions of functions. It states that to differentiate a composite function, you first differentiate the outer function and then multiply it by the derivative of the inner function.

In the exercise problem, the function can be seen as a composition of simpler functions
  • The expression inside the square root can be considered one function.
  • The square root itself is another function.
We apply the chain rule to differentiate each part, as seen when taking the natural logarithm of the function. Differentiating requires identifying these nested functions and handling them systematically.

Use of the chain rule is also evident in the differentiation step, where individual terms like \(x+1\) and \(2x+1\) are differentiated using simpler derivative rules.
Natural Logarithms
Natural logarithms serve as a powerful tool in calculus, particularly for solving exponential functions. In the context of logarithmic differentiation, natural logs help transform products and quotients inside a function into simpler sums and differences.

In the exercise, we transform the complicated product and quotient into a more manageable form by taking the natural logarithm of both sides. This reduces \( y = (x+1)^5 (2x+1)^{-\frac{5}{2}} \) to \( \ln(y) = 5 \ln(x+1) - \frac{5}{2} \ln(2x+1) \).

Using logarithms in this way helps to handle exponents without having to deal directly with complex expressions or expansive polynomial multiplication. This transformation is key to simplifying the differentiation process.
Exponential Simplification
Exponential simplification is often necessary when dealing with derivatives of functions that involve powers or roots. Simplifying these expressions can make it much more manageable to apply calculus techniques.

In this problem, the function is simplified initially by expressing the square root as a fractional exponent, \( \left( \frac{(x+1)^{10}}{(2x+1)^{5}} \right)^{\frac{1}{2}} \), which simplifies further to \( (x+1)^5 (2x+1)^{-\frac{5}{2}} \).

Exponential simplification helps break down the steps to find the derivative and makes further processes like factoring and combining terms possible. It aids in breaking down a daunting expression into smaller, easier-to-manage components, which facilitates the solving process.

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Most popular questions from this chapter

Volume The region enclosed by the curve \(y=\operatorname{sech} x,\) the \(x\) -axis, and the lines \(x=\pm \ln \sqrt{3}\) is revolved about the \(x\) -axis to generate a solid. Find the volume of the solid.

Which of the following functions grow faster than \(\ln x\) as \(x \rightarrow \infty ?\) Which grow at the same rate as \(\ln x ?\) Which grow slower? a. \(\log _{2}\left(x^{2}\right)\) b. \(\log _{10} 10 x\) c. \(1 / \sqrt{x}\) d. \(1 / x^{2}\) e. \(x-2 \ln x\) f. \(e^{-x}\) g. \(\ln (\ln x)\) h. \(\ln (2 x+5)\)

Use your graphing utility. Graph \(f(x)=\sin ^{-1} x\) together with its first two derivatives. Comment on the behavior of \(f\) and the shape of its graph in relation to the signs and values of \(f^{\prime}\) and \(f^{\prime \prime}\)

a. Graph \(f(x)=(\sin x)^{\tan x}\) on the interval \(-7 \leq x \leq 7 .\) How do you account for the gaps in the graph? How wide are the gaps? b. Now graph \(f\) on the interval \(0 \leq x \leq \pi .\) The function is not defined at \(x=\pi / 2,\) but the graph has no break at this point. What is going on? What value does the graph appear to give for \(f\) at \(x=\pi / 2 ?\) (Hint: Use 1 'Hôpital's Rule to find lim \(f\) as \(\left.x \rightarrow(\pi / 2)^{-} \text {and } x \rightarrow(\pi / 2)^{+} .\right)\) c. Continuing with the graphs in part (b), find max \(f\) and \(\min f\) as accurately as you can and estimate the values of \(x\) at which they are taken on.

True, or false? As \(x \rightarrow \infty\) a. \(\frac{1}{x+3}=O\left(\frac{1}{x}\right)\) b. \(\frac{1}{x}+\frac{1}{x^{2}}=O\left(\frac{1}{x}\right)\) c. \(\frac{1}{x}-\frac{1}{x^{2}}=o\left(\frac{1}{x}\right)\) d. \(2+\cos x=O(2)\) g. \(\ln (\ln x)=O(\ln x)\) h. \(\ln (x)=o\left(\ln \left(x^{2}+1\right)\right)\)

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