5.35 problem 35

Internal problem ID [113]

Book: Differential equations and linear algebra, 3rd ed., Edwards and Penney
Section: Section 1.6, Substitution methods and exact equations. Page 74
Problem number: 35.
ODE order: 1.
ODE degree: 1.

CAS Maple gives this as type [_exact]

\[ \boxed {\frac {y}{x}+\left (\ln \left (x \right )+y^{2}\right ) y^{\prime }=-x^{3}} \]

Solution by Maple

Time used: 0.016 (sec). Leaf size: 307

dsolve(x^3+y(x)/x+(ln(x)+y(x)^2)*diff(y(x),x) = 0,y(x), singsol=all)
 

\begin{align*} y \left (x \right ) &= \frac {\left (-3 x^{4}-12 c_{1} +\sqrt {64 \ln \left (x \right )^{3}+9 \left (x^{4}+4 c_{1} \right )^{2}}\right )^{\frac {2}{3}}-4 \ln \left (x \right )}{2 \left (-3 x^{4}-12 c_{1} +\sqrt {64 \ln \left (x \right )^{3}+9 \left (x^{4}+4 c_{1} \right )^{2}}\right )^{\frac {1}{3}}} \\ y \left (x \right ) &= \frac {i \left (-\left (-3 x^{4}-12 c_{1} +\sqrt {64 \ln \left (x \right )^{3}+9 \left (x^{4}+4 c_{1} \right )^{2}}\right )^{\frac {2}{3}}-4 \ln \left (x \right )\right ) \sqrt {3}-\left (-3 x^{4}-12 c_{1} +\sqrt {64 \ln \left (x \right )^{3}+9 \left (x^{4}+4 c_{1} \right )^{2}}\right )^{\frac {2}{3}}+4 \ln \left (x \right )}{4 \left (-3 x^{4}-12 c_{1} +\sqrt {64 \ln \left (x \right )^{3}+9 \left (x^{4}+4 c_{1} \right )^{2}}\right )^{\frac {1}{3}}} \\ y \left (x \right ) &= \frac {i \left (\left (-3 x^{4}-12 c_{1} +\sqrt {64 \ln \left (x \right )^{3}+9 \left (x^{4}+4 c_{1} \right )^{2}}\right )^{\frac {2}{3}}+4 \ln \left (x \right )\right ) \sqrt {3}-\left (-3 x^{4}-12 c_{1} +\sqrt {64 \ln \left (x \right )^{3}+9 \left (x^{4}+4 c_{1} \right )^{2}}\right )^{\frac {2}{3}}+4 \ln \left (x \right )}{4 \left (-3 x^{4}-12 c_{1} +\sqrt {64 \ln \left (x \right )^{3}+9 \left (x^{4}+4 c_{1} \right )^{2}}\right )^{\frac {1}{3}}} \\ \end{align*}

Solution by Mathematica

Time used: 1.864 (sec). Leaf size: 307

DSolve[x^3+y[x]/x+(Log[x]+y[x]^2)*y'[x] == 0,y[x],x,IncludeSingularSolutions -> True]
                                                                                    
                                                                                    
 

\begin{align*} y(x)\to \frac {-4 \log (x)+\left (-3 x^4+\sqrt {64 \log ^3(x)+9 \left (x^4-4 c_1\right ){}^2}+12 c_1\right ){}^{2/3}}{2 \sqrt [3]{-3 x^4+\sqrt {64 \log ^3(x)+9 \left (x^4-4 c_1\right ){}^2}+12 c_1}} \\ y(x)\to \frac {i \left (\sqrt {3}+i\right ) \left (-3 x^4+\sqrt {64 \log ^3(x)+9 \left (x^4-4 c_1\right ){}^2}+12 c_1\right ){}^{2/3}+\left (4+4 i \sqrt {3}\right ) \log (x)}{4 \sqrt [3]{-3 x^4+\sqrt {64 \log ^3(x)+9 \left (x^4-4 c_1\right ){}^2}+12 c_1}} \\ y(x)\to \frac {\left (-1-i \sqrt {3}\right ) \left (-3 x^4+\sqrt {64 \log ^3(x)+9 \left (x^4-4 c_1\right ){}^2}+12 c_1\right ){}^{2/3}+\left (4-4 i \sqrt {3}\right ) \log (x)}{4 \sqrt [3]{-3 x^4+\sqrt {64 \log ^3(x)+9 \left (x^4-4 c_1\right ){}^2}+12 c_1}} \\ \end{align*}