40.14.7 problem 28

Internal problem ID [6778]
Book : Schaums Outline. Theory and problems of Differential Equations, 1st edition. Frank Ayres. McGraw Hill 1952
Section : Chapter 19. Linear equations with variable coefficients (Misc. types). Supplemetary problems. Page 132
Problem number : 28
Date solved : Monday, January 27, 2025 at 02:30:17 PM
CAS classification : [[_2nd_order, _missing_x], [_2nd_order, _reducible, _mu_y_y1]]

\begin{align*} y y^{\prime \prime }&={y^{\prime }}^{2} \left (1-y^{\prime } \cos \left (y\right )+y y^{\prime } \sin \left (y\right )\right ) \end{align*}

✓ Solution by Maple

Time used: 0.060 (sec). Leaf size: 22

dsolve(y(x)*diff(y(x),x$2)=diff(y(x),x)^2*(1-diff(y(x),x)*cos(y(x))+y(x)*diff(y(x),x)*sin(y(x)) ),y(x), singsol=all)
 

\begin{align*} y &= c_1 \\ \sin \left (y\right )+c_1 \ln \left (y\right )-x -c_2 &= 0 \\ \end{align*}

✓ Solution by Mathematica

Time used: 0.460 (sec). Leaf size: 63

DSolve[y[x]*D[y[x],{x,2}]==D[y[x],x]^2*(1-D[y[x],x]*Cos[y[x]]+y[x]*D[y[x],x]*Sin[y[x]] ),y[x],x,IncludeSingularSolutions -> True]
 

\begin{align*} y(x)\to \text {InverseFunction}[\sin (\text {$\#$1})+c_1 \log (\text {$\#$1})\&][x+c_2] \\ y(x)\to \text {InverseFunction}[\sin (\text {$\#$1})-c_1 \log (\text {$\#$1})\&][x+c_2] \\ y(x)\to \text {InverseFunction}[\sin (\text {$\#$1})+c_1 \log (\text {$\#$1})\&][x+c_2] \\ \end{align*}