1.18 problem 2(d)

1.18.1 Solving as quadrature ode
1.18.2 Maple step by step solution

Internal problem ID [6122]
Internal file name [OUTPUT/5370_Sunday_June_05_2022_03_35_36_PM_57886836/index.tex]

Book: Differential Equations: Theory, Technique, and Practice by George Simmons, Steven Krantz. McGraw-Hill NY. 2007. 1st Edition.
Section: Chapter 1. What is a differential equation. Section 1.2 THE NATURE OF SOLUTIONS. Page 9
Problem number: 2(d).
ODE order: 1.
ODE degree: 1.

The type(s) of ODE detected by this program : "quadrature"

Maple gives the following as the ode type

[_quadrature]

\[ \boxed {\left (x^{2}+1\right ) y^{\prime }=x} \]

1.18.1 Solving as quadrature ode

Integrating both sides gives \begin {align*} y &= \int { \frac {x}{x^{2}+1}\,\mathop {\mathrm {d}x}}\\ &= \frac {\ln \left (x^{2}+1\right )}{2}+c_{1} \end {align*}

Summary

The solution(s) found are the following \begin{align*} \tag{1} y &= \frac {\ln \left (x^{2}+1\right )}{2}+c_{1} \\ \end{align*}

Figure 35: Slope field plot

Verification of solutions

\[ y = \frac {\ln \left (x^{2}+1\right )}{2}+c_{1} \] Verified OK.

1.18.2 Maple step by step solution

\[ \begin {array}{lll} & {} & \textrm {Let's solve}\hspace {3pt} \\ {} & {} & \left (x^{2}+1\right ) y^{\prime }=x \\ \bullet & {} & \textrm {Highest derivative means the order of the ODE is}\hspace {3pt} 1 \\ {} & {} & y^{\prime } \\ \bullet & {} & \textrm {Solve for the highest derivative}\hspace {3pt} \\ {} & {} & y^{\prime }=\frac {x}{x^{2}+1} \\ \bullet & {} & \textrm {Integrate both sides with respect to}\hspace {3pt} x \\ {} & {} & \int y^{\prime }d x =\int \frac {x}{x^{2}+1}d x +c_{1} \\ \bullet & {} & \textrm {Evaluate integral}\hspace {3pt} \\ {} & {} & y=\frac {\ln \left (x^{2}+1\right )}{2}+c_{1} \\ \bullet & {} & \textrm {Solve for}\hspace {3pt} y \\ {} & {} & y=\frac {\ln \left (x^{2}+1\right )}{2}+c_{1} \end {array} \]

Maple trace

`Methods for first order ODEs: 
--- Trying classification methods --- 
trying a quadrature 
<- quadrature successful`
 

Solution by Maple

Time used: 0.016 (sec). Leaf size: 14

dsolve((1+x^2)*diff(y(x),x)=x,y(x), singsol=all)
 

\[ y \left (x \right ) = \frac {\ln \left (x^{2}+1\right )}{2}+c_{1} \]

Solution by Mathematica

Time used: 0.003 (sec). Leaf size: 18

DSolve[(1+x^2)*y'[x]==x,y[x],x,IncludeSingularSolutions -> True]
 

\[ y(x)\to \frac {1}{2} \log \left (x^2+1\right )+c_1 \]