7.2.12 4.5

7.2.12.1 [609] problem number 1

problem number 609

Added January 10, 2019.

Problem 2.4.5.1 from Handbook of first order partial differential equations by Polyanin, Zaitsev, Moussiaux.

Solve for \(w(x,y)\) \[ w_x + a \sinh (\lambda x) \cosh (\mu y) w_y = 0 \]

Mathematica ✓

ClearAll["Global`*"]; 
pde =  D[w[x, y], x] + a*Sinh[lambda*x]*Cosh[mu*y]*D[w[x, y], y] == 0; 
sol =  AbsoluteTiming[TimeConstrained[DSolve[pde, w[x, y], {x, y}], 60*10]];
 

\[\left \{\left \{w(x,y)\to c_1\left (\frac {4 \tan ^{-1}\left (\tanh \left (\frac {\mu y}{2}\right )\right )}{\mu }-\frac {2 a \cosh (\lambda x)}{\lambda }\right )\right \}\right \}\]

Maple ✓

restart; 
pde := diff(w(x,y),x)+a*sinh(lambda*x)*cosh(mu*y)*diff(w(x,y),y) = 0; 
cpu_time := timelimit(60*10,CodeTools[Usage](assign('sol',pdsolve(pde,w(x,y))),output='realtime'));
 

\[w \left (x , y\right ) = \textit {\_F1} \left (\frac {-a \mu \cosh \left (\lambda x \right )+2 \lambda \arctan \left ({\mathrm e}^{\mu y}\right )}{a \lambda \mu }\right )\]

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7.2.12.2 [610] problem number 2

problem number 610

Added January 10, 2019.

Problem 2.4.5.2 from Handbook of first order partial differential equations by Polyanin, Zaitsev, Moussiaux.

Solve for \(w(x,y)\) \[ w_x + a \cosh (\lambda x) \sinh (\mu y) w_y = 0 \]

Mathematica ✓

ClearAll["Global`*"]; 
pde =  D[w[x, y], x] + a*Cosh[lambda*x]*Sinh[mu*y]*D[w[x, y], y] == 0; 
sol =  AbsoluteTiming[TimeConstrained[DSolve[pde, w[x, y], {x, y}], 60*10]];
 

\[\left \{\left \{w(x,y)\to c_1\left (\frac {\log \left (\tanh ^2\left (\frac {\mu y}{2}\right )\right )}{\mu }-\frac {2 a \sinh (\lambda x)}{\lambda }\right )\right \}\right \}\]

Maple ✓

restart; 
pde := diff(w(x,y),x)+a*cosh(lambda*x)*sinh(mu*y)*diff(w(x,y),y) = 0; 
cpu_time := timelimit(60*10,CodeTools[Usage](assign('sol',pdsolve(pde,w(x,y))),output='realtime'));
 

\[w \left (x , y\right ) = \textit {\_F1} \left (\frac {-a \mu \,{\mathrm e}^{\lambda x}+a \mu \,{\mathrm e}^{-\lambda x}-4 \lambda \arctanh \left ({\mathrm e}^{\mu y}\right )}{2 a \lambda \mu }\right )\]

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7.2.12.3 [611] problem number 3

problem number 611

Added January 10, 2019.

Problem 2.4.5.3 from Handbook of first order partial differential equations by Polyanin, Zaitsev, Moussiaux.

Solve for \(w(x,y)\) \[ w_x + \left ( y^2 -2 \lambda ^2 \tanh ^2(\lambda x) - 2 \lambda ^2 \coth ^2(\lambda x) \right ) w_y = 0 \]

Mathematica ✓

ClearAll["Global`*"]; 
pde =  D[w[x, y], x] + (y^2 - 2*lambda^2*Tanh[lambda*x]^2 - 2*lambda^2*Coth[lambda*x]^2)*D[w[x, y], y] == 0; 
sol =  AbsoluteTiming[TimeConstrained[DSolve[pde, w[x, y], {x, y}], 60*10]];
 

\[\left \{\left \{w(x,y)\to c_1\left (\frac {e^{-4 \lambda x} \left (16 \lambda ^2 x e^{4 \lambda x} \left (e^{4 \lambda x}+1\right )+y \left (e^{4 \lambda x}+1\right ) \left (e^{4 \lambda x}-1\right )^2+2 \lambda \left (e^{4 \lambda x}-1\right ) \left (-2 e^{4 \lambda x} (2 x y+3)+e^{8 \lambda x}+1\right )\right )}{2 \left (-y e^{4 \lambda x}+2 \lambda \left (e^{4 \lambda x}+1\right )+y\right )}\right )\right \}\right \}\]

Maple ✓

restart; 
pde := diff(w(x,y),x)+(y^2 -2 *lambda^2*tanh(lambda*x)^2 - 2*lambda^2*coth(lambda*x)^2)*diff(w(x,y),y) = 0; 
cpu_time := timelimit(60*10,CodeTools[Usage](assign('sol',pdsolve(pde,w(x,y))),output='realtime'));
 

\[w \left (x , y\right ) = \textit {\_F1} \left (\frac {-4 \lambda \left (\coth ^{2}\left (\lambda x \right )\right ) \sinh \left (\lambda x \right )+4 \lambda \sinh \left (\lambda x \right )+\left (8 \lambda \cosh \left (\lambda x \right )-4 y \sinh \left (\lambda x \right )\right ) \coth \left (\lambda x \right )}{2 \left (-4 \sinh \left (\lambda x \right )-3 \sinh \left (3 \lambda x \right )+\sinh \left (5 \lambda x \right )\right ) \lambda \coth \left (\lambda x \right )+\left (-\lambda \left (\coth ^{2}\left (\lambda x \right )\right )-y \coth \left (\lambda x \right )+\lambda \right ) \cosh \left (3 \lambda x \right )+\left (\lambda \left (\coth ^{2}\left (\lambda x \right )\right )+y \coth \left (\lambda x \right )-\lambda \right ) \cosh \left (5 \lambda x \right )+\left (4 \lambda \left (\coth ^{2}\left (\lambda x \right )\right ) \sinh \left (\lambda x \right )-4 \lambda \sinh \left (\lambda x \right )+\left (-8 \lambda \cosh \left (\lambda x \right )+4 y \sinh \left (\lambda x \right )\right ) \coth \left (\lambda x \right )\right ) \ln \left (\frac {\cosh \left (\lambda x \right )-\sinh \left (\lambda x \right )}{\sinh \left (\lambda x \right )}\right )+\left (-4 \lambda \left (\coth ^{2}\left (\lambda x \right )\right ) \sinh \left (\lambda x \right )+4 \lambda \sinh \left (\lambda x \right )+\left (8 \lambda \cosh \left (\lambda x \right )-4 y \sinh \left (\lambda x \right )\right ) \coth \left (\lambda x \right )\right ) \ln \left (\frac {\cosh \left (\lambda x \right )+\sinh \left (\lambda x \right )}{\sinh \left (\lambda x \right )}\right )}\right )\]

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7.2.12.4 [612] problem number 4

problem number 612

Added January 10, 2019.

Problem 2.4.5.4 from Handbook of first order partial differential equations by Polyanin, Zaitsev, Moussiaux.

Solve for \(w(x,y)\) \[ w_x + \left ( y^2 +\lambda (a+b)-2 a b -a(a+\lambda ) \tanh ^2(\lambda x) - b(b+\lambda ) \coth ^2(\lambda x) \right ) w_y = 0 \]

Mathematica ✓

ClearAll["Global`*"]; 
pde =  D[w[x, y], x] + (y^2 + lambda*(a + b) - 2*a*b - a*(a + lambda)*Tanh[lambda*x]^2 - b*(b + lambda)*Coth[lambda*x]^2)*D[w[x, y], y] == 0; 
sol =  AbsoluteTiming[TimeConstrained[DSolve[pde, w[x, y], {x, y}], 60*10]];
 

\[\left \{\left \{w(x,y)\to c_1\left (\frac {\lambda e^{-2 x (a+b)} \left ((a+b-\lambda ) F_1\left (-\frac {a+b}{\lambda };-\frac {2 b}{\lambda },-\frac {2 a}{\lambda };-\frac {a+b-\lambda }{\lambda };e^{2 \lambda x},-e^{2 \lambda x}\right ) \left (a \left (-2 e^{2 \lambda x}+3 e^{4 \lambda x}-1\right )+\left (e^{2 \lambda x}+1\right ) \left (b \left (3 e^{2 \lambda x}-1\right )-y e^{2 \lambda x}+y\right )\right )+4 b (a+b) e^{2 \lambda x} \left (e^{4 \lambda x}-1\right ) F_1\left (1-\frac {a+b}{\lambda };1-\frac {2 b}{\lambda },-\frac {2 a}{\lambda };-\frac {a+b-2 \lambda }{\lambda };e^{2 \lambda x},-e^{2 \lambda x}\right )-4 a (a+b) e^{2 \lambda x} \left (e^{4 \lambda x}-1\right ) F_1\left (1-\frac {a+b}{\lambda };-\frac {2 b}{\lambda },1-\frac {2 a}{\lambda };-\frac {a+b-2 \lambda }{\lambda };e^{2 \lambda x},-e^{2 \lambda x}\right )\right )}{(a+b) (a+b-\lambda ) \left (a \left (e^{2 \lambda x}-1\right )^2+\left (e^{2 \lambda x}+1\right ) \left (b e^{2 \lambda x}+b-y e^{2 \lambda x}+y\right )\right )}\right )\right \}\right \}\]

Maple ✓

restart; 
pde := diff(w(x,y),x)+(y^2 +lambda*(a+b)-2*a*b -a*(a+lambda)*tanh(lambda*x)^2 - b*(b+lambda)*coth(lambda*x)^2)*diff(w(x,y),y) = 0; 
cpu_time := timelimit(60*10,CodeTools[Usage](assign('sol',pdsolve(pde,w(x,y))),output='realtime'));
 

\[w \left (x , y\right ) = \textit {\_F1} \left (\frac {\left (2 a +3 \lambda \right ) \left (a \left (\cosh ^{2}\left (\lambda x \right )\right )+b \left (\cosh ^{2}\left (\lambda x \right )\right )-y \cosh \left (\lambda x \right ) \sinh \left (\lambda x \right )-a \right ) \left (\frac {\cosh \left (\lambda x \right )}{\sinh \left (\lambda x \right )}\right )^{\frac {-2 a -\lambda }{\lambda }} \left (-\frac {1}{\sinh \left (\lambda x \right )^{2}}\right )^{\frac {a +b}{\lambda }} \left (\sinh ^{2}\left (\lambda x \right )\right )}{4 \left (b -\frac {\lambda }{2}\right ) \lambda \hypergeom \left (\left [2, -\frac {2 b -3 \lambda }{2 \lambda }\right ], \left [\frac {2 a +5 \lambda }{2 \lambda }\right ], \frac {\cosh ^{2}\left (\lambda x \right )}{\sinh \left (\lambda x \right )^{2}}\right ) \left (\cosh ^{2}\left (\lambda x \right )\right )+2 \left (a +\frac {3 \lambda }{2}\right ) \left (\cosh \left (\lambda x \right )-1\right ) \left (\cosh \left (\lambda x \right )+1\right ) \left (y \cosh \left (\lambda x \right ) \sinh \left (\lambda x \right )+\left (a +b \right ) \left (\cosh ^{2}\left (\lambda x \right )\right )-a -\lambda \right ) \hypergeom \left (\left [1, \frac {-2 b +\lambda }{2 \lambda }\right ], \left [\frac {2 a +3 \lambda }{2 \lambda }\right ], \frac {\cosh ^{2}\left (\lambda x \right )}{\sinh \left (\lambda x \right )^{2}}\right )}\right )\]

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7.2.12.5 [613] problem number 5

problem number 613

Added January 10, 2019.

Problem 2.4.5.5 from Handbook of first order partial differential equations by Polyanin, Zaitsev, Moussiaux.

Solve for \(w(x,y)\) \[ \sinh (\lambda y) w_x + a \cosh (\beta x) w_y = 0 \]

Mathematica ✓

ClearAll["Global`*"]; 
pde =  Sinh[lambda*y]*D[w[x, y], x] + a*Cosh[beta*x]*D[w[x, y], y] == 0; 
sol =  AbsoluteTiming[TimeConstrained[DSolve[pde, w[x, y], {x, y}], 60*10]];
 

\[\left \{\left \{w(x,y)\to c_1\left (\frac {\cosh (\lambda y)}{\lambda }-\frac {a \sinh (\beta x)}{\beta }\right )\right \}\right \}\]

Maple ✓

restart; 
pde := sinh(lambda*y)*diff(w(x,y),x)+a*cosh(beta*x)*diff(w(x,y),y) = 0; 
cpu_time := timelimit(60*10,CodeTools[Usage](assign('sol',pdsolve(pde,w(x,y))),output='realtime'));
 

\[w \left (x , y\right ) = \textit {\_F1} \left (\frac {-a \lambda \sinh \left (\beta x \right )+\beta \cosh \left (\lambda y \right )}{a \beta \lambda }\right )\]

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7.2.12.6 [614] problem number 6

problem number 614

Added January 10, 2019.

Problem 2.4.5.6 from Handbook of first order partial differential equations by Polyanin, Zaitsev, Moussiaux.

Solve for \(w(x,y)\) \[ \left ( a x^n \cosh ^m(\lambda y)+ b x \right ) w_x + \sinh ^k(\beta y) w_y = 0 \]

Mathematica ✗

ClearAll["Global`*"]; 
pde =  (a*x^n*Cosh[lambda*y]^m + b*x)*D[w[x, y], x] + Sinh[beta*y]^k*D[w[x, y], y] == 0; 
sol =  AbsoluteTiming[TimeConstrained[DSolve[pde, w[x, y], {x, y}], 60*10]];
 

Failed

Maple ✓

restart; 
pde := (a*x^n*cosh(lambda*y)^m+b*x)*diff(w(x,y),x)+sinh(beta*y)^k*diff(w(x,y),y) = 0; 
cpu_time := timelimit(60*10,CodeTools[Usage](assign('sol',pdsolve(pde,w(x,y))),output='realtime'));
 

\[w \left (x , y\right ) = \textit {\_F1} \left (\left (n -1\right ) a \left (\int \left (\cosh ^{m}\left (\lambda y \right )\right ) \left (\sinh ^{-k}\left (\beta y \right )\right ) {\mathrm e}^{\left (n -1\right ) b \left (\int \left (\sinh ^{-k}\left (\beta y \right )\right )d y \right )}d y \right )+x^{-n +1} {\mathrm e}^{\left (n -1\right ) b \left (\int \left (\sinh ^{-k}\left (\beta y \right )\right )d y \right )}\right )\]

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