5.15 problem 4 and 16(ii)

Internal problem ID [12965]

Book: DIFFERENTIAL EQUATIONS by Paul Blanchard, Robert L. Devaney, Glen R. Hall. 4th edition. Brooks/Cole. Boston, USA. 2012
Section: Chapter 1. First-Order Differential Equations. Exercises section 1.6 page 89
Problem number: 4 and 16(ii).
ODE order: 1.
ODE degree: 1.

CAS Maple gives this as type [_quadrature]

\[ \boxed {w^{\prime }-w \cos \left (w\right )=0} \] With initial conditions \begin {align*} [w \left (3\right ) = 1] \end {align*}

Solution by Maple

Time used: 0.407 (sec). Leaf size: 20

dsolve([diff(w(t),t)=w(t)*cos( w(t)),w(3) = 1],w(t), singsol=all)
 

\[ w \left (t \right ) = \operatorname {RootOf}\left (\int _{\textit {\_Z}}^{1}\frac {\sec \left (\textit {\_a} \right )}{\textit {\_a}}d \textit {\_a} +t -3\right ) \]

Solution by Mathematica

Time used: 0.0 (sec). Leaf size: 0

DSolve[{w'[t]==w[t]*Cos[ w[t]],{w[3]==1}},w[t],t,IncludeSingularSolutions -> True]
 

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