2.3 problem 3

Internal problem ID [4242]

Book: Mathematical Methods in the Physical Sciences. third edition. Mary L. Boas. John Wiley. 2006
Section: Chapter 8, Ordinary differential equations. Section 2. Separable equations. page 398
Problem number: 3.
ODE order: 1.
ODE degree: 1.

CAS Maple gives this as type [_separable]

\[ \boxed {y^{\prime } \sin \left (x \right )-y \ln \left (y\right )=0} \] With initial conditions \begin {align*} \left [y \left (\frac {\pi }{3}\right ) = {\mathrm e}\right ] \end {align*}

Solution by Maple

Time used: 0.438 (sec). Leaf size: 16

dsolve([diff(y(x),x)*sin(x)=y(x)*ln(y(x)),y(1/3*Pi) = exp(1)],y(x), singsol=all)
 

\[ y \left (x \right ) = {\mathrm e}^{\left (\csc \left (x \right )-\cot \left (x \right )\right ) \sqrt {3}} \]

Solution by Mathematica

Time used: 0.209 (sec). Leaf size: 19

DSolve[{y'[x]*Sin[x]==y[x]*Log[y[x]],{y[Pi/3]==Exp[1]}},y[x],x,IncludeSingularSolutions -> True]
 

\begin{align*} y(x)\to e^{\sqrt {3} \tan \left (\frac {x}{2}\right )} \\ \end{align*}