6.4.11 4.4

6.4.11.1 [1092] Problem 1

problem number 1092

Added Feb. 23, 2019.

Problem Chapter 4.4.4.1, from Handbook of first order partial differential equations by Polyanin, Zaitsev, Moussiaux.

Solve for \(w(x,y)\) \[ a w_x + b w_y = (c \coth (\lambda x) + k \coth (\mu y)) w \]

Mathematica ✓

ClearAll["Global`*"]; 
pde =  a*D[w[x, y], x] + b*D[w[x, y], y] == (c*Coth[lambda*x] + k*Coth[mu*y])*w[x, y]; 
sol =  AbsoluteTiming[TimeConstrained[DSolve[pde, w[x, y], {x, y}], 60*10]];
 

\[\left \{\left \{w(x,y)\to \sinh ^{\frac {c}{a \lambda }}(\lambda x) c_1\left (y-\frac {b x}{a}\right ) e^{\frac {k (\log (\tanh (\mu y))+\log (\cosh (\mu y)))}{b \mu }}\right \}\right \}\]

Maple ✓

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

\[w \left ( x,y \right ) ={\it \_F1} \left ( {\frac {ya-bx}{a}} \right ) \left ( {\rm coth} \left (\lambda \,x\right )-1 \right ) ^{-1/2\,{\frac {c}{a\lambda }}} \left ( {\rm coth} \left (\lambda \,x\right )+1 \right ) ^{-1/2\,{\frac {c}{a\lambda }}} \left ( {\rm coth} \left (\mu \,y\right )-1 \right ) ^{-1/2\,{\frac {k}{b\mu }}} \left ( {\rm coth} \left (\mu \,y\right )+1 \right ) ^{-1/2\,{\frac {k}{b\mu }}}\]

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6.4.11.2 [1093] Problem 2

problem number 1093

Added Feb. 23, 2019.

Problem Chapter 4.4.4.2, from Handbook of first order partial differential equations by Polyanin, Zaitsev, Moussiaux.

Solve for \(w(x,y)\) \[ a w_x + b w_y = c \coth (\lambda x +\mu y) w \]

Mathematica ✓

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

\[\left \{\left \{w(x,y)\to c_1\left (y-\frac {b x}{a}\right ) \exp \left (\frac {c (\log (\tanh (\lambda x+\mu y))+\log (\cosh (\lambda x+\mu y)))}{a \lambda +b \mu }\right )\right \}\right \}\]

Maple ✓

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

\[w \left ( x,y \right ) ={\it \_F1} \left ( {\frac {ya-bx}{a}} \right ) \left ( {\rm coth} \left (\lambda \,x+\mu \,y\right )-1 \right ) ^{-{\frac {c}{2\,a\lambda +2\,b\mu }}} \left ( {\rm coth} \left (\lambda \,x+\mu \,y\right )+1 \right ) ^{-{\frac {c}{2\,a\lambda +2\,b\mu }}}\]

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6.4.11.3 [1094] Problem 3

problem number 1094

Added Feb. 23, 2019.

Problem Chapter 4.4.4.3, from Handbook of first order partial differential equations by Polyanin, Zaitsev, Moussiaux.

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

Mathematica ✓

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

\[\left \{\left \{w(x,y)\to c_1\left (\frac {y}{x}\right ) \exp \left (\frac {a x (\log (\tanh (\lambda x+\mu y))+\log (\cosh (\lambda x+\mu y)))}{\lambda x+\mu y}\right )\right \}\right \}\]

Maple ✓

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

\[w \left ( x,y \right ) ={\it \_F1} \left ( {\frac {y}{x}} \right ) \left ( {\rm coth} \left (\lambda \,x+\mu \,y\right )-1 \right ) ^{-1/2\,{a \left ( {\frac {\mu \,y}{x}}+\lambda \right ) ^{-1}}} \left ( {\rm coth} \left (\lambda \,x+\mu \,y\right )+1 \right ) ^{-1/2\,{a \left ( {\frac {\mu \,y}{x}}+\lambda \right ) ^{-1}}}\]

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6.4.11.4 [1095] Problem 4

problem number 1095

Added Feb. 23, 2019.

Problem Chapter 4.4.4.4, from Handbook of first order partial differential equations by Polyanin, Zaitsev, Moussiaux.

Solve for \(w(x,y)\) \[ a w_x + b \coth ^n(\lambda x) w_y = (c \coth ^m(\mu x)+s \coth ^k(\beta y)) w \]

Mathematica ✓

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

\[\left \{\left \{w(x,y)\to c_1\left (y-\frac {b \coth ^{n+1}(\lambda x) \, _2F_1\left (1,\frac {n+1}{2};\frac {n+3}{2};\coth ^2(\lambda x)\right )}{a \lambda n+a \lambda }\right ) \exp \left (\int _1^x\frac {s \coth ^k\left (\frac {\beta \left (-b \, _2F_1\left (1,\frac {n+1}{2};\frac {n+3}{2};\coth ^2(\lambda x)\right ) \coth ^{n+1}(\lambda x)+a \lambda (n+1) y+b \coth ^{n+1}(\lambda K[1]) \, _2F_1\left (1,\frac {n+1}{2};\frac {n+3}{2};\coth ^2(\lambda K[1])\right )\right )}{a \lambda (n+1)}\right )+c \coth ^m(\mu K[1])}{a}dK[1]\right )\right \}\right \}\]

Maple ✓

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

\[w \left ( x,y \right ) ={\it \_F1} \left ( -\int \!{\frac {b \left ( {\rm coth} \left (\lambda \,x\right ) \right ) ^{n}}{a}}\,{\rm d}x+y \right ) {{\rm e}^{\int ^{x}\!{\frac {1}{a} \left ( c \left ( {\rm coth} \left (\mu \,{\it \_b}\right ) \right ) ^{m}+s \left ( -{\rm coth} \left (\beta \, \left ( -\int \!{\frac {b \left ( {\rm coth} \left ({\it \_b}\,\lambda \right ) \right ) ^{n}}{a}}\,{\rm d}{\it \_b}+\int \!{\frac {b \left ( {\rm coth} \left (\lambda \,x\right ) \right ) ^{n}}{a}}\,{\rm d}x-y \right ) \right ) \right ) ^{k} \right ) }{d{\it \_b}}}}\]

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6.4.11.5 [1096] Problem 5

problem number 1096

Added Feb. 23, 2019.

Problem Chapter 4.4.4.5, from Handbook of first order partial differential equations by Polyanin, Zaitsev, Moussiaux.

Solve for \(w(x,y)\) \[ a w_x + b \coth ^n(\lambda y) w_y = (c \coth ^m(\mu x)+s \coth ^k(\beta y)) w \]

Mathematica ✓

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

\[\left \{\left \{w(x,y)\to c_1\left (\frac {\coth ^{1-n}(\lambda y) \, _2F_1\left (1,\frac {1}{2}-\frac {n}{2};\frac {3}{2}-\frac {n}{2};\coth ^2(\lambda y)\right )}{\lambda -\lambda n}-\frac {b x}{a}\right ) \exp \left (\int _1^y\frac {\left (s \coth ^k(\beta K[1])+c \coth ^m\left (\frac {-a \mu \, _2F_1\left (1,\frac {1}{2}-\frac {n}{2};\frac {3}{2}-\frac {n}{2};\coth ^2(\lambda y)\right ) \coth ^{1-n}(\lambda y)+b \lambda \mu x-b \lambda \mu n x+a \mu \coth ^{1-n}(\lambda K[1]) \, _2F_1\left (1,\frac {1}{2}-\frac {n}{2};\frac {3}{2}-\frac {n}{2};\coth ^2(\lambda K[1])\right )}{b \lambda -b \lambda n}\right )\right ) \coth ^{-n}(\lambda K[1])}{b}dK[1]\right )\right \}\right \}\]

Maple ✓

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

\[w \left ( x,y \right ) ={\it \_F1} \left ( -{\frac {a\int \! \left ( {\rm coth} \left (y\lambda \right ) \right ) ^{-n}\,{\rm d}y}{b}}+x \right ) {{\rm e}^{\int ^{y}\!{\frac { \left ( {\rm coth} \left ({\it \_b}\,\lambda \right ) \right ) ^{-n}}{b} \left ( c \left ( -{\rm coth} \left (-\mu \,\int \!{\frac { \left ( {\rm coth} \left ({\it \_b}\,\lambda \right ) \right ) ^{-n}a}{b}}\,{\rm d}{\it \_b}-\mu \, \left ( -{\frac {a\int \! \left ( {\rm coth} \left (y\lambda \right ) \right ) ^{-n}\,{\rm d}y}{b}}+x \right ) \right ) \right ) ^{m}+s \left ( {\rm coth} \left (\beta \,{\it \_b}\right ) \right ) ^{k} \right ) }{d{\it \_b}}}}\]

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