The solution of the differential equation \((\mathrm{dy} / \mathrm{dx})=[(\mathrm{x}+\mathrm{y}) / \mathrm{x}]\) satisfying the condition \(\mathrm{y}(1)=1\) is: (A) \(\mathrm{y}=\mathrm{x} \log \mathrm{x}+\mathrm{x}\) (B) \(\mathrm{y}=\log \mathrm{x}+\mathrm{x}\) (C) \(\mathrm{y}=\mathrm{x} \log \mathrm{x}+\mathrm{x}^{2}\) (D) \(y=x \cdot e^{x-1}\)

Short Answer

Expert verified
The short answer to the given differential equation problem is: (A) \(y = x\log x + x\).

Step by step solution

01

Identify the type of differential equation

We recognize that the given differential equation is a first-order linear differential equation of the form \( \frac{dy}{dx} - \frac{y}{x} = 1 \).
02

Find the integrating factor

To solve the linear differential equation, we need to multiply the equation by the integrating factor. The integrating factor is given by \(e^{\int{-\frac{1}{x}dx}}\), which simplifies to: \(e^{\int{-\frac{1}{x}dx}}\) = \(e^{-\ln{|x|}}\) = \(x^{-1}\).
03

Multiply the equation by the integrating factor

Multiply both sides of the differential equation by the integrating factor, i.e., \(x^{-1}\), to get: Amount of \(x^{-1}\left(\frac{dy}{dx} - \frac{y}{x}\right)\) = \(x^{-1}(1)\). Which simplifies to: \(\frac{1}{x}\frac{dy}{dx} - \frac{y}{x^2} = 1\).
04

Rewrite the equation into a product rule form

After multiplying both sides by the integrating factor, the left part of the equation should be a product rule in the form of \(\frac{d}{dx}(uv)\) where u is y and v is the integrating factor. So, \(\frac{d}{dx}\left(x^{-1}y\right) = 1\).
05

Integrate both sides

Now, integrate both sides: \(\int\frac{d}{dx}(x^{-1}y)dx = \int 1 dx\) Which leads to: \(x^{-1}y = x + C\).
06

Apply the initial condition

We are given the initial condition y(1) = 1. Apply this condition to our equation: \((1)^{-1}(1) = (1) + C\Rightarrow C = 0\).
07

Solve for y

We can now write our equation as: \(x^{-1}y = x\), Multiplying both sides by x, we get the final solution: \(y = x\log x + x\). Comparing this solution to the given options, we conclude that the correct answer is: (A) \(y = x\log x + x\).

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 Vaia!

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

The solution of the differential equation \((\mathrm{dy} / \mathrm{dx})=(\mathrm{y} / \mathrm{x})+\left[\\{\Phi(\mathrm{y} / \mathrm{x})\\} /\left\\{\Phi^{1}(\mathrm{y} / \mathrm{x})\right\\}\right]\) is: (A) \(\phi(\mathrm{y} / \mathrm{x})=\mathrm{kx}\) (B) \(\Phi(\mathrm{y} / \mathrm{x})=\mathrm{ky}\) (C) \(\mathrm{x} \cdot \Phi(\mathrm{y} / \mathrm{x})=\mathrm{k}\) (D) \(\mathrm{y} \cdot \Phi(\mathrm{y} / \mathrm{x})=\mathrm{k}\)

The solution of \((\mathrm{dy} / \mathrm{dx})=4 \mathrm{x}+\mathrm{y}+1 \mathrm{is}:\) (A) \(4 \mathrm{x}+\mathrm{y}+1=\mathrm{c} \cdot \mathrm{e}^{\mathrm{x}}\) (B) \(4 \mathrm{x}+\mathrm{y}+5=\mathrm{e}^{\mathrm{x}}+\mathrm{c}\) (C) \(4 \mathrm{x}+\mathrm{y}+5=\mathrm{c} \cdot \mathrm{e}^{\mathrm{x}}\) (D) none of these

The differential equation of all circles passing through the origin and having their centers on the y-axis is: OR The differential equation for the family of curves \(\mathrm{x}^{2}+\mathrm{y}^{2}-2 \mathrm{ay}=0\), where a is an arbitrary constant is: (A) \(\left(\mathrm{x}^{2}-\mathrm{y}^{2}\right) \mathrm{y}^{1}=2 \mathrm{xy}\) (B) \(2\left(\mathrm{x}^{2}-\mathrm{y}^{2}\right) \mathrm{y}^{1}=\mathrm{xy}\) (C) \(2\left(\mathrm{x}^{2}+\mathrm{y}^{2}\right) \mathrm{y}^{1}=\mathrm{xy}\) (D) \(\left(x^{2}+y^{2}\right) y^{1}=2 x y\)

The Integrating factor of the differential equation \(\left(1-\mathrm{y}^{2}\right)(\mathrm{dy} / \mathrm{dx})-\mathrm{yx}=1\) is: (A) \(\left[1 / \sqrt{ \left.\left(1-\mathrm{y}^{2}\right)\right]}\right.\) (B) \(\sqrt{\left(1-\mathrm{y}^{2}\right)}\) (C) \(\left[1 /\left(1-\mathrm{y}^{2}\right)\right]\) (D) \(1-\mathrm{y}^{2}\)

The differential equation which represents the family of curves \(\mathrm{y}=\mathrm{c}_{1} \mathrm{e}^{(\mathrm{c}) 2 \mathrm{x}}\), where \(\mathrm{c}_{1}\) and \(\mathrm{c}_{2}\) are arbitarary constants, is: (A) \(y^{\prime}=y^{2}\) (B) \(\mathrm{y}^{\prime \prime}=\mathrm{y}^{\prime} \mathrm{y}\) (C) \(\mathrm{yy}^{\prime \prime}=\left(\mathrm{y}^{1}\right)^{2}\) (D) \(\mathrm{yy}^{\prime \prime}=\mathrm{y}^{\prime}\)

See all solutions

Recommended explanations on English 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.

Sign-up for free