38.9 problem Ex 9

Internal problem ID [10326]

Book: An elementary treatise on differential equations by Abraham Cohen. DC heath publishers. 1906
Section: Chapter IX, Miscellaneous methods for solving equations of higher order than first. Article 62. Summary. Page 144
Problem number: Ex 9.
ODE order: 2.
ODE degree: 1.

CAS Maple gives this as type [[_2nd_order, _missing_x], [_2nd_order, _reducible, _mu_xy]]

\[ \boxed {y^{\prime \prime }+{y^{\prime }}^{2}+1=0} \]

Solution by Maple

Time used: 0.032 (sec). Leaf size: 19

dsolve(diff(y(x),x$2)+diff(y(x),x)^2+1=0,y(x), singsol=all)
 

\[ y \left (x \right ) = \ln \left (-\frac {c_{1} \tan \left (x \right )-c_{2}}{\sec \left (x \right )}\right ) \]

Solution by Mathematica

Time used: 1.838 (sec). Leaf size: 16

DSolve[y''[x]+y'[x]^2+1==0,y[x],x,IncludeSingularSolutions -> True]
 

\begin{align*} y(x)\to \log (\cos (x-c_1))+c_2 \\ \end{align*}