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Question: missing ode solution when adding singsol=all

Question:missing ode solution when adding singsol=all

nm 7930 Maple 2023
ode singular dsolve differential-equations
June 09 2023
2

When adding singsol=all to this ode in the first example, dsolve returns nothing. But it should have returned the general solution if it can not find singular solution. This is what it does always as can be seen from the second example given below.

Why did dsolve return nothing in the first example? Is this a bug?

319824

> 

interface(version);

`Standard Worksheet Interface, Maple 2023.0, Windows 10, March 6 2023 Build ID 1689885`

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restart;

319824

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ode:=y(x)=x*diff(y(x),x)+ a*diff(y(x),x)/(sqrt(1+diff(y(x),x)^2));
sol_1:=dsolve(ode,y(x));
sol_2:=dsolve(ode,y(x),singsol=all);

y(x) = x*(diff(y(x), x))+a*(diff(y(x), x))/(1+(diff(y(x), x))^2)^(1/2)

y(x) = x*c__1+a*c__1/(c__1^2+1)^(1/2)

"sol_2 := "

> 

ode:=diff(y(x),x)^2-(1+2*x*y(x))*diff(y(x),x)+2*x*y(x) = 0;
sol_1:=dsolve(ode,y(x));
sol_2:=dsolve(ode,y(x), singsol=all)

(diff(y(x), x))^2-(1+2*y(x)*x)*(diff(y(x), x))+2*y(x)*x = 0

y(x) = c__1*exp(x^2), y(x) = x+c__1

y(x) = c__1*exp(x^2), y(x) = x+c__1

> 

 

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