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Question: dsolve gives 'series/RootOf'. Received: 'unable to compute series' on first order ode

Question:dsolve gives 'series/RootOf'. Received: 'unable to compute series' on first order ode

nm 9899 Maple 2024
ode dsolve differential-equations
August 22 2024
2

This ode has solution when solving for the IC by hand. But Maple gives new error I did not see before when asking it to solve the ode with IC. 

No error if asked to solve the ODE without the IC.

Is this new error in dsolve? I have no earlier Maple versions to check. Below is worksheet. Solving for the IC by hand gives the solution which odetest verified.

> 

restart;
> 

interface(version);

`Standard Worksheet Interface, Maple 2024.1, Windows 10, June 25 2024 Build ID 1835466`

> 

Physics:-Version();

`The "Physics Updates" version in the MapleCloud is 1789 and is the same as the version installed in this computer, created 2024, August 10, 8:50 hours Pacific Time.`

> 

ode := diff(y(x), x) = sqrt(2)*sqrt(-(y(x) - 6)*(2*y(x) - 3))/(-y(x) + 6);
IC:=y(0)=3;

diff(y(x), x) = 2^(1/2)*(-(y(x)-6)*(2*y(x)-3))^(1/2)/(-y(x)+6)

y(0) = 3

> 

sol:=dsolve(ode);

x-(1/4)*(-4*y(x)^2+30*y(x)-36)^(1/2)-(9/8)*arcsin((4/9)*y(x)-5/3)+c__1 = 0

> 

sol_with_IC:=dsolve([ode,IC]); #why this error??

Error, (in dsolve) when calling 'series/RootOf'. Received: 'unable to compute series'

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#lets solve for the IC by hand:
eq:=eval(sol,[y(x)=3,x=0])

-(1/4)*18^(1/2)+(9/8)*arcsin(1/3)+c__1 = 0

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C_sol:=PDEtools:-Solve(eq,_C1);

c__1 = (3/4)*2^(1/2)-(9/8)*arcsin(1/3)

> 

my_new_sol:=eval(sol,C_sol)

x-(1/4)*(-4*y(x)^2+30*y(x)-36)^(1/2)-(9/8)*arcsin((4/9)*y(x)-5/3)+(3/4)*2^(1/2)-(9/8)*arcsin(1/3) = 0

> 

odetest(my_new_sol,[ode,IC])

[0, 0]

> 

 


 

Download internal_error_when_unable_to_find_solution_august_22_2024.mw
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