/*! 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 50 Verify that \(y=-\ln \left(e^{2}... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

Verify that \(y=-\ln \left(e^{2}-x\right)\) satisfies \(d y / d x=e^{y},\) with \(y=-2\) when \(x=0\)

Short Answer

Expert verified
Yes, the function satisfies \( dy/dx = e^y \) and the initial condition is met.

Step by step solution

01

Find the derivative of y with respect to x

Given the function \( y = -\ln(e^2 - x) \), we need to differentiate it with respect to \( x \). Using the chain rule, the derivative of \( y \) is \( dy/dx = -\frac{1}{e^2 - x} \times (-1) = \frac{1}{e^2 - x} \).
02

Substitute y into e^y and check the equality

Substitute \( y = -\ln(e^2 - x) \) into \( e^y \) to verify \( dy/dx = e^y \). We have \( e^y = e^{-\ln(e^2-x)} \), which simplifies to \( \frac{1}{e^{\ln(e^2-x)}} = \frac{1}{e^2-x} \).
03

Verify the equality dy/dx = e^y

From Step 1, \( \frac{dy}{dx} = \frac{1}{e^2 - x} \). From Step 2, \( e^y = \frac{1}{e^2-x} \). Since both expressions are equal, \( \frac{dy}{dx} = e^y \), verifying the condition is met.
04

Verify initial condition y=-2 when x=0

Substitute \( x = 0 \) into the original function to verify the initial condition. \( y = -\ln(e^2 - 0) = -\ln(e^2) = -2 \). The initial condition \( y = -2 \) when \( x = 0 \) is satisfied.

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.

Calculus
Calculus is a branch of mathematics that deals with the study of change and motion. It helps us understand how systems evolve over time and rates at which these changes occur. In this exercise, we delve into differential calculus, which focuses on the concept of taking derivatives. Derivatives are essential for finding the rate of change of a variable in relation to another variable. This forms the core of many scientific and engineering problems.

When working with functions like \( y = -\ln(e^2 - x) \), finding the derivative \( \frac{dy}{dx} \) allows us to understand how \( y \) changes as \( x \) changes. Here, we specifically compute the derivative to ensure it equals a given function, \( e^y \). Key tools from calculus that facilitate this process include rules like the chain rule (which we will discuss shortly), which are fundamental in managing complex operations. This structural approach not only broadens understanding but also simplifies solving these equations.
Chain Rule
The chain rule is a core principle in calculus used to differentiate composite functions. A composite function is essentially a function within another function. For example, if you have a function \( y = -\ln(e^2 - x) \), this is composed of an outer function, \(-\ln(u)\), and an inner function, \(u = e^2 - x\).
  • The derivative of the outer function in terms of the inner function, is \(-1/u\).
  • The derivative of the inner function \( u = e^2 - x \) is \(-1\).
Multiplying these, as the chain rule prescribes, yields a combined derivative: \(-(-1/u) = \frac{1}{e^2 - x}\). This shows how the chain rule streamlines the process of finding derivatives for complex compositions.

Using the chain rule simplifies tackling complex functions by breaking them into manageable components, ensuring accuracy in differentiation tasks. This aids in effortlessly verifying equations like \( \frac{dy}{dx} = e^y \) by ensuring all parts of a composite are correctly addressed.
Initial Conditions
Initial conditions provide specific values at the outset to verify the solutions of differential equations. These conditions illustrate a point on the function that the solution must satisfy to be valid within the problem's context. In our exercise, the initial condition states \( y = -2 \) when \( x = 0 \).

To verify this, we substitute \( x = 0 \) into the original function. When \( y = -\ln(e^2 - 0) = -\ln(e^2) \), simplifying provides \( y = -2 \). This matches our initial condition, confirming that the solution satisfies both the differential equation and the specific starting values. Using initial conditions like this helps in narrowing down solutions to those that are physically meaningful and consistent with given data.
  • Initial conditions are crucial for confirming the relevance and accuracy of general solutions.
  • They ensure the solution adheres to the specific scenario posed by the exercise or real-world problem.
Thus, initial conditions play a pivotal role in practical applications where precise outcomes are necessary.

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

(a) Find the error in the following calculation: $$\begin{aligned} \lim _{x \rightarrow 1} \frac{x^{3}-x^{2}+x-1}{x^{3}-x^{2}} &=\lim _{x \rightarrow 1} \frac{3 x^{2}-2 x+1}{3 x^{2}-2 x} \\ &=\lim _{x \rightarrow 1} \frac{6 x-2}{6 x-2}=1 \end{aligned}$$ (b) Find the correct limit.

The thin lens equation in physics is $$\frac{1}{s}+\frac{1}{S}=\frac{1}{f}$$ where \(s\) is the object distance from the lens, \(S\) is the image distance from the lens, and \(f\) is the focal length of the lens. Suppose that a certain lens has a focal length of \(6 \mathrm{cm}\) and that an object is moving toward the lens at the rate of \(2 \mathrm{cm} / \mathrm{s} .\) How fast is the image distance changing at the instant when the object is \(10 \mathrm{cm}\) from the lens? Is the image moving away from the lens or toward the lens?

Make a conjecture about the equations of horizontal asymptotes, if any, by graphing the equation with a graphing utility; then check your answer using L'Hôpital's rule. $$y=(\ln x)^{1 / x}$$

Verify that L'Hôpital's rule is of no help in finding the limit; then find the limit, if it exists, by some other method. $$\lim _{x \rightarrow+\infty} \frac{x(2+\sin x)}{x^{2}+1}$$

There is a myth that circulates among beginning calculus students which states that all indeterminate forms of types \(0^{0}, \infty^{0},\) and \(1^{\infty}\) have value 1 because "anything to the zero power is \(1^{\prime \prime}\) and \(^{\prime \prime} 1\) to any power is \(1 . "\) The fallacy is that \(0^{0}, \infty^{0},\) and \(1^{\infty}\) are not powers of numbers, but rather descriptions of limits. The following examples, which were suggested by Prof. Jack Staib of Drexel University, show that such indeterminate forms can have any positive real value: (a) \(\lim _{x \rightarrow 0^{+}}\left[x^{(\ln a) /(1+\ln x)}\right]=a \quad\left(\text { form } 0^{0}\right)\) (b) \(\lim _{x \rightarrow+\infty}\left[x^{(\ln a) /(1+\ln x)}\right]=a \quad\left(\text { form } \infty^{0}\right)\) (c) \(\lim _{x \rightarrow 0}\left[(x+1)^{(\ln a) / x}\right]=a \quad\left(\text { form } 1^{\infty}\right)\). Verify these results.

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.