4.11 problem 11

Internal problem ID [12647]

Book: Ordinary Differential Equations by Charles E. Roberts, Jr. CRC Press. 2010
Section: Chapter 2. The Initial Value Problem. Exercises 2.2, page 53
Problem number: 11.
ODE order: 1.
ODE degree: 1.

CAS Maple gives this as type [[_homogeneous, `class C`], _dAlembert]

\[ \boxed {y^{\prime }-\sqrt {\frac {y-4}{x}}=0} \]

Solution by Maple

Time used: 0.031 (sec). Leaf size: 38

dsolve(diff(y(x),x)=sqrt( (y(x)-4)/x ),y(x), singsol=all)
 

\[ -\ln \left (\frac {-y \left (x \right )+4+x}{x}\right )+2 \,\operatorname {arctanh}\left (\sqrt {\frac {y \left (x \right )-4}{x}}\right )-\ln \left (x \right )-c_{1} = 0 \]

Solution by Mathematica

Time used: 0.294 (sec). Leaf size: 29

DSolve[y'[x]==Sqrt[ (y[x]-4)/x ],y[x],x,IncludeSingularSolutions -> True]
                                                                                    
                                                                                    
 

\begin{align*} y(x)\to x+c_1 \sqrt {x}+4+\frac {c_1{}^2}{4} \\ y(x)\to 4 \\ \end{align*}