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Question: What is the meaning of this error in pdsolve command.

Question:What is the meaning of this error in pdsolve command.

sharmamanjeet391 5 Maple 2020
pde pdsolve differential-equations
February 26 2023
1

problemfilepdsolve.mw
 

> 

eq1 := diff(p(x, t), x)-p(x, t)*(1/(p(x, t)^2*q(x, t)^(1/3)))

diff(p(x, t), x)-1/(p(x, t)*q(x, t)^(1/3))

 (1)
> 

eq2 := diff(q(x, t), x)-(-3*q(x, t))*(1/(p(x, t)^2*q(x, t)^(1/3)))

diff(q(x, t), x)+3*q(x, t)^(2/3)/p(x, t)^2

 (2)
> 

pdsolve({eq1, eq2})

Error, (in pdsolve/sys) found the element '_F2' repeated in the indication of blocks variables

  
> 

eq3 := diff(p(x), x)-p(x)*(1/(p(x)^2*q(x)^(1/3)))

diff(p(x), x)-1/(p(x)*q(x)^(1/3))

 (3)
> 

eq4 := diff(q(x), x)-(-3*q(x))*(1/(p(x)^2*q(x)^(1/3)))

diff(q(x), x)+3*q(x)^(2/3)/p(x)^2

 (4)
> 

dsolve({eq3, eq4})

[{q(x) = -27/(_C1*x+_C2)^3}, {p(x) = (-3*(diff(q(x), x))*q(x)^(2/3))^(1/2)/(diff(q(x), x)), p(x) = -(-3*(diff(q(x), x))*q(x)^(2/3))^(1/2)/(diff(q(x), x))}]

 (5)
> 

eq5 := diff(p(x, t), x)-x = 0

diff(p(x, t), x)-x = 0

 (6)
> 

pdsolve(eq5)

p(x, t) = (1/2)*x^2+_F1(t)

 (7)
> 

eq6 := diff(p(x), x)-x = 0

diff(p(x), x)-x = 0

 (8)
> 

dsolve(eq6)

p(x) = (1/2)*x^2+_C1

 (9)
> 

NULL

``

 (10)


Help me in finding the solution of system eq1 and eq2.

Download problemfilepdsolve.mw

 
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