15.1.21 problem 21

Internal problem ID [2861]
Book : Differential Equations by Alfred L. Nelson, Karl W. Folley, Max Coral. 3rd ed. DC heath. Boston. 1964
Section : Exercise 5, page 21
Problem number : 21
Date solved : Monday, January 27, 2025 at 06:20:32 AM
CAS classification : [_separable]

\begin{align*} y^{\prime }&=\frac {y}{x} \end{align*}

With initial conditions

\begin{align*} y \left (1\right )&=3 \end{align*}

✓ Solution by Maple

Time used: 0.003 (sec). Leaf size: 7

dsolve([diff(y(x),x)=y(x)/x,y(1) = 3],y(x), singsol=all)
 

\[ y = 3 x \]

✓ Solution by Mathematica

Time used: 0.024 (sec). Leaf size: 8

DSolve[{D[y[x],x]==y[x]/x,y[1]==3},y[x],x,IncludeSingularSolutions -> True]
 

\[ y(x)\to 3 x \]