/*! 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 28 Find the derivative of \(y\) wit... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

Find the derivative of \(y\) with respect to \(x, t,\) or \(\theta\) as appropriate. $$y=\frac{x \ln x}{1+\ln x}$$

Short Answer

Expert verified
The derivative is \(y' = \frac{1 + 2\ln x + \ln^2 x}{(1 + \ln x)^2}\)."

Step by step solution

01

Identify the Function Structure

Identify the structure of the function. The given function is \(y = \frac{x \ln x}{1 + \ln x}\). This is a quotient of two functions of \(x\).
02

Recall the Quotient Rule

The Quotient Rule states that the derivative of \(\frac{u}{v}\) is \(\frac{u'v - uv'}{v^2}\), where \(u\) and \(v\) are functions of \(x\). Identify \(u(x) = x \ln x\) and \(v(x) = 1 + \ln x\).
03

Differentiate the Numerator

Find the derivative of the numerator \(u(x) = x \ln x\). Use the product rule: \(u' = (x)'(\ln x) + (x)((\ln x)') = \ln x + 1\).
04

Differentiate the Denominator

Find the derivative of the denominator \(v(x) = 1 + \ln x\). The derivative is \(v' = 0 + \frac{1}{x} = \frac{1}{x}\).
05

Apply the Quotient Rule

Substitute \(u\), \(u'\), \(v\), and \(v'\) into the Quotient Rule formula: \(y' = \frac{(\ln x + 1)(1 + \ln x) - \left(x \ln x \right)\left(\frac{1}{x}\right)}{(1 + \ln x)^2}\).
06

Simplify the Expression

Simplify the expression for the derivative: \(y' = \frac{\ln x + \ln^2 x + 1 + \ln x - \ln x}{(1 + \ln x)^2} = \frac{1 + 2\ln x + \ln^2 x}{(1 + \ln x)^2}\).

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!

Key Concepts

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

Understanding Derivatives
In calculus, a derivative represents the rate at which a function changes. It gives the slope of the function at any given point. When you differentiate a function, you are essentially finding a formula that tells you the gradient of the function as it changes with respect to a variable, such as x.

Here's how to think about it:
  • The derivative of a function at a point is the slope of the tangent line to the function's graph at that point.
  • If the derivative is positive, the function is increasing.
  • If the derivative is negative, the function is decreasing.
For the function given in the exercise, you need to determine how it changes as x varies. Calculating the derivative will tell us how y changes in relation to x.
Applying the Quotient Rule
The quotient rule is a technique used to find the derivative of a function that is the division of two other functions. For a function in the form of \( \frac{u(x)}{v(x)} \), the quotient rule provides a method to differentiate it.

The rule is as follows:
  • If \( y = \frac{u}{v} \), then \( y' = \frac{u'v - uv'}{v^2} \).
  • Here,\( u' \) and \( v' \) represent the derivatives of \( u \) and \( v \) with respect to x.
  • It's essentially saying "the derivative of the top function times the bottom, minus the derivative of the bottom function times the top, divided by the bottom function squared."
In our exercise, \( u(x) = x \ln x \) and \( v(x) = 1 + \ln x \). By applying the quotient rule, you can find the derivative of the entire function as shown in the solution steps.
Using the Product Rule
In the numerator of the function \( y = \frac{x \ln x}{1 + \ln x} \), we encounter a scenario where we must use the product rule. The product rule is used when differentiating a product of two functions.

Here's the rule:
  • If \( z = f(x) \cdot g(x) \), then \( z' = f'(x)g(x) + f(x)g'(x) \).
  • This means you take the derivative of the first function and multiply by the second function, plus the first function times the derivative of the second function.
For \( u(x) = x \ln x \), apply the product rule to find: \( u' = (x)'(\ln x) + (x)((\ln x)') = \ln x + 1 \). Knowing this allows us to take another step in differentiating the entire function correctly.
Grasping Differentiation
Differentiation is the process of finding a derivative, which is key in understanding how functions change. It helps in comprehending how variables relate, particularly in calculus.

Key points about differentiation:
  • Differentiation applies to virtually any function you come across.
  • It is a fundamental tool in calculus for finding rates of change.
  • Through differentiation, you obtain a new function, the derivative, that provides insights into the behavior of the original function.
In the given exercise, differentiation was used extensively to navigate through more complex functions involving both the product and quotient rule. The goal is to simplify and find how y changes concerning x effectively.

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

Find the domain and range of each composite Iunction. Then graph the composites on separate screens. Do the graphs make sense in each case? Give reasons for your answers. Comment on any differences you see. a. \(y=\tan ^{-1}(\tan x)\) b. \(y=\tan \left(\tan ^{-1} x\right)\)

A spherical iron ball 8 in. in diameter is coated with a layer of ice of uniform thickness. If the ice melts at the rate of 10 in \(^{3} / \mathrm{min}\), how fast is the thickness of the ice decreasing when it is 2 in. thick? How fast is the outer surface area of ice decreasing?

You will explore some functions and their inverses together with their derivatives and tangent line approximations at specified points. Perform the following steps using your CAS: a. Plot the function \(y=f(x)\) together with its derivative over the given interval. Explain why you know that \(f\) is one-to-one over the interval. b. Solve the equation \(y=f(x)\) for \(x\) as a function of \(y,\) and name the resulting inverse function \(g\). c. Find the equation for the tangent line to \(f\) at the specified point \(\left(x_{0}, f\left(x_{0}\right)\right)\) d. Find the equation for the tangent line to \(g\) at the point \(\left(f\left(x_{0}\right), x_{0}\right)\) located symmetrically across the \(45^{\circ}\) line \(y=x\) (which is the graph of the identity function). Use Theorem 3 to find the slope of this tangent line. e. Plot the functions \(f\) and \(g\), the identity, the two tangent lines, and the line segment joining the points \(\left(x_{0}, f\left(x_{0}\right)\right)\) and \(\left(f\left(x_{0}\right), x_{0}\right)\) Discuss the symmetries you see across the main diagonal. $$y=x^{3}-3 x^{2}-1, \quad 2 \leq x \leq 5, \quad x_{0}=\frac{27}{10}$$

Find the derivative of \(y\) with respect to the given independent variable. $$y=\log _{2}\left(\frac{x^{2} e^{2}}{2 \sqrt{x+1}}\right)$$

Use your graphing utility. Graph the rational function \(y=\left(2-x^{2}\right) / x^{2} .\) Then graph \(y=\) \(\cos \left(2 \sec ^{-1} x\right)\) in the same graphing window. What do you see? Explain.

See all solutions

Recommended explanations on Math Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.