77.1.120 problem 147 (page 224)

Internal problem ID [18010]
Book : V.V. Stepanov, A course of differential equations (in Russian), GIFML. Moscow (1958)
Section : All content
Problem number : 147 (page 224)
Date solved : Tuesday, January 28, 2025 at 11:19:55 AM
CAS classification : [[_high_order, _missing_x]]

\begin{align*} y^{\prime \prime \prime \prime }-2 y^{\prime \prime }&=0 \end{align*}

Solution by Maple

Time used: 0.001 (sec). Leaf size: 26

dsolve(diff(y(x),x$4)-2*diff(y(x),x$2)=0,y(x), singsol=all)
 
\[ y = c_{1} +c_{2} x +c_{3} {\mathrm e}^{\sqrt {2}\, x}+c_4 \,{\mathrm e}^{-\sqrt {2}\, x} \]

Solution by Mathematica

Time used: 0.075 (sec). Leaf size: 42

DSolve[D[y[x],{x,4}]-2*D[y[x],{x,2}]==0,y[x],x,IncludeSingularSolutions -> True]
 
\[ y(x)\to \frac {1}{2} e^{-\sqrt {2} x} \left (c_1 e^{2 \sqrt {2} x}+c_2\right )+c_4 x+c_3 \]