29.34.21 problem 1023

Internal problem ID [5592]
Book : Ordinary differential equations and their solutions. By George Moseley Murphy. 1960
Section : Various 34
Problem number : 1023
Date solved : Monday, January 27, 2025 at 12:13:02 PM
CAS classification : [_quadrature]

\begin{align*} {y^{\prime }}^{3}+y^{\prime }-y&=0 \end{align*}

Solution by Maple

Time used: 0.039 (sec). Leaf size: 215

dsolve(diff(y(x),x)^3+diff(y(x),x)-y(x) = 0,y(x), singsol=all)
 
\begin{align*} x -6 \left (\int _{}^{y \left (x \right )}\frac {\left (108 \textit {\_a} +12 \sqrt {81 \textit {\_a}^{2}+12}\right )^{{1}/{3}}}{\left (108 \textit {\_a} +12 \sqrt {81 \textit {\_a}^{2}+12}\right )^{{2}/{3}}-12}d \textit {\_a} \right )-c_{1} &= 0 \\ \frac {-12 \left (\int _{}^{y \left (x \right )}\frac {\left (108 \textit {\_a} +12 \sqrt {81 \textit {\_a}^{2}+12}\right )^{{1}/{3}}}{-6-6 i \sqrt {3}-\left (108 \textit {\_a} +12 \sqrt {81 \textit {\_a}^{2}+12}\right )^{{2}/{3}}}d \textit {\_a} \right )+i \left (-c_{1} +x \right ) \sqrt {3}+x -c_{1}}{1+i \sqrt {3}} &= 0 \\ \frac {12 \left (\int _{}^{y \left (x \right )}\frac {\left (108 \textit {\_a} +12 \sqrt {81 \textit {\_a}^{2}+12}\right )^{{1}/{3}}}{-\left (108 \textit {\_a} +12 \sqrt {81 \textit {\_a}^{2}+12}\right )^{{2}/{3}}+\left (\sqrt {3}+3 i\right )^{2}}d \textit {\_a} \right )+i \left (-c_{1} +x \right ) \sqrt {3}+c_{1} -x}{i \sqrt {3}-1} &= 0 \\ \end{align*}

Solution by Mathematica

Time used: 0.534 (sec). Leaf size: 335

DSolve[(D[y[x],x])^3 +D[y[x],x]-y[x]==0,y[x],x,IncludeSingularSolutions -> True]
 
\begin{align*} y(x)\to \text {InverseFunction}\left [\int \frac {\sqrt [3]{\sqrt {729 \text {$\#$1}^2+108}-27 \text {$\#$1}}}{2^{2/3} \left (\sqrt {729 \text {$\#$1}^2+108}-27 \text {$\#$1}\right )^{2/3}-6 \sqrt [3]{2}}d\text {$\#$1}\&\right ]\left [-\frac {x}{6}+c_1\right ] \\ y(x)\to \text {InverseFunction}\left [\int \frac {\sqrt [3]{\sqrt {729 \text {$\#$1}^2+108}-27 \text {$\#$1}}}{-i 2^{2/3} \sqrt {3} \left (\sqrt {729 \text {$\#$1}^2+108}-27 \text {$\#$1}\right )^{2/3}+2^{2/3} \left (\sqrt {729 \text {$\#$1}^2+108}-27 \text {$\#$1}\right )^{2/3}-6 i \sqrt [3]{2} \sqrt {3}-6 \sqrt [3]{2}}d\text {$\#$1}\&\right ]\left [\frac {x}{12}+c_1\right ] \\ y(x)\to \text {InverseFunction}\left [\int \frac {\sqrt [3]{\sqrt {729 \text {$\#$1}^2+108}-27 \text {$\#$1}}}{i 2^{2/3} \sqrt {3} \left (\sqrt {729 \text {$\#$1}^2+108}-27 \text {$\#$1}\right )^{2/3}+2^{2/3} \left (\sqrt {729 \text {$\#$1}^2+108}-27 \text {$\#$1}\right )^{2/3}+6 i \sqrt [3]{2} \sqrt {3}-6 \sqrt [3]{2}}d\text {$\#$1}\&\right ]\left [\frac {x}{12}+c_1\right ] \\ y(x)\to 0 \\ \end{align*}