1.23 problem 23

Internal problem ID [4934]

Book: Fundamentals of Differential Equations. By Nagle, Saff and Snider. 9th edition. Boston. Pearson 2018.
Section: Chapter 2, First order differential equations. Section 2.2, Separable Equations. Exercises. page 46
Problem number: 23.
ODE order: 1.
ODE degree: 1.

CAS Maple gives this as type [_separable]

\[ \boxed {y^{\prime }-2 t \cos \left (y\right )^{2}=0} \] With initial conditions \begin {align*} \left [y \left (0\right ) = \frac {\pi }{4}\right ] \end {align*}

Solution by Maple

Time used: 0.094 (sec). Leaf size: 10

dsolve([diff(y(t),t)=2*t*cos(y(t))^2,y(0) = 1/4*Pi],y(t), singsol=all)
 

\[ y \left (t \right ) = \arctan \left (t^{2}+1\right ) \]

Solution by Mathematica

Time used: 0.428 (sec). Leaf size: 11

DSolve[{y'[t]==2*t*Cos[y[t]]^2,{y[0]==Pi/4}},y[t],t,IncludeSingularSolutions -> True]
 

\[ y(t)\to \arctan \left (t^2+1\right ) \]