Consider the differential equation \(\frac{{dy}}{{dx}} + \frac{y}

Consider the differential equation \(\frac{{dy}}{{dx}} + \frac{y}
| Consider the differential equation \(\frac{{dy}}{{dx}} + \frac{y}{x} = {x^2}\) under the condition that y = 1 when x = 1 is ______ then

A. Integration factor is x<sup style="">2</sup>

B. Integration factor is x

C. The solution of the differential equation is 4xy = x<sup style="">4</sup> + 3

D. The solution of the differential equation is 4xy = y<sup style="">4</sup> &ndash; 3

Please scroll down to see the correct answer and solution guide.

Right Answer is:

SOLUTION

Explanation:

Given:

\(\frac{{dy}}{{dx}} + \frac{y}{x} = {x^2}x = 1,\;y = 1\)

It is linear differential equation in ‘y’

\(P = \frac{1}{x}\;;Q = {x^2}\)

\(IF = {e^{\smallint \frac{1}{x}dx\;}} = {e^{\log x}} = x\)

Solution is y(IF) = ∫ Q(IF) dx

\(\Rightarrow xy = \smallint {x^3}dx = \frac{{{x^4}}}{4} + c\)

\( \Rightarrow y = \frac{{{x^3}}}{4} + \frac{c}{x}\;\;\; - - - \left( 1 \right)\)

\(x = 1,\;y = 1,\;\left( 1 \right) \Rightarrow 1 = \frac{1}{4} + c \Rightarrow c = \frac{3}{4}\)

∴ Solution is \(y = \frac{{{x^3}}}{4} + \frac{3}{{4x}}\)  (or) 4xy = x4 + 3