7.2.29 8.6

7.2.29.1 [789] problem number 1

problem number 789

Added Feb. 7, 2019.

Problem 2.8.6.1 from Handbook of first order partial differential equations by Polyanin, Zaitsev, Moussiaux.

Solve for \(w(x,y)\)

\[ w_x + \left ( f(x) y^2 -f(x) g(x) y+ g'(x)\right ) w_y = 0 \]

Mathematica ✗

ClearAll["Global`*"]; 
pde =  D[w[x, y], x] + (f[x]*y^2 - f[x]*g[x]*y + Derivative[1][g][x])*D[w[x, y], y] == 0; 
sol =  AbsoluteTiming[TimeConstrained[DSolve[pde, w[x, y], {x, y}], 60*10]];
 

Failed

Maple ✗

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

sol=()

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7.2.29.2 [790] problem number 2

problem number 790

Added Feb. 7, 2019.

Problem 2.8.6.2 from Handbook of first order partial differential equations by Polyanin, Zaitsev, Moussiaux.

Solve for \(w(x,y)\)

\[ w_x - \left ( f'(x) y^2 -f(x) g(x) y+ g(x)\right ) w_y = 0 \]

Mathematica ✗

ClearAll["Global`*"]; 
pde =  D[w[x, y], x] - (Derivative[1][f][x]*y^2 - f[x]*g[x]*y + g[x])*D[w[x, y], y] == 0; 
sol =  AbsoluteTiming[TimeConstrained[DSolve[pde, w[x, y], {x, y}], 60*10]];
 

Failed

Maple ✓

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

\[w \left (x , y\right ) = \textit {\_F1} \left (\frac {y \left (\int \frac {\left (\frac {d}{d x}f \left (x \right )\right ) {\mathrm e}^{\int f \left (x \right ) g \left (x \right )d x}}{f \left (x \right )^{2}}d x \right ) f \left (x \right )-{\mathrm e}^{-\left (\int \frac {-f \left (x \right )^{2} g \left (x \right )+2 \frac {d}{d x}f \left (x \right )}{f \left (x \right )}d x \right )} f \left (x \right )-\left (\int \frac {\left (\frac {d}{d x}f \left (x \right )\right ) {\mathrm e}^{\int f \left (x \right ) g \left (x \right )d x}}{f \left (x \right )^{2}}d x \right )}{y f \left (x \right )-1}\right )\]

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7.2.29.3 [791] problem number 3

problem number 791

Added Feb. 7, 2019.

Problem 2.8.6.3 from Handbook of first order partial differential equations by Polyanin, Zaitsev, Moussiaux.

Solve for \(w(x,y)\)

\[ w_x + \left ( g(x)(y-f(x))^2 + f'(x)\right ) w_y = 0 \]

Mathematica ✓

ClearAll["Global`*"]; 
pde =  D[w[x, y], x] + (g[x]*(y - f[x])^2 + Derivative[1][f][x])*D[w[x, y], y] == 0; 
sol =  AbsoluteTiming[TimeConstrained[DSolve[pde, w[x, y], {x, y}], 60*10]];
 

\[\left \{\left \{w(x,y)\to c_1\left (\int _1^xg(K[2])dK[2]+\frac {1}{y-f(x)}\right )\right \}\right \}\]

Maple ✓

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

\[w \left (x , y\right ) = \textit {\_F1} \left (\frac {\left (y -f \left (x \right )\right ) \left (\int g \left (x \right )d x \right )+1}{y -f \left (x \right )}\right )\]

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7.2.29.4 [792] problem number 4

problem number 792

Added Feb. 7, 2019.

Problem 2.8.6.4 from Handbook of first order partial differential equations by Polyanin, Zaitsev, Moussiaux.

Solve for \(w(x,y)\)

\[ w_x + \left ( \frac {f'(x)}{g(x)} y^2 - \frac {g'(x)}{f(x)}\right ) w_y = 0 \]

Mathematica ✗

ClearAll["Global`*"]; 
pde =  D[w[x, y], x] + ((Derivative[1][f][x]*y^2)/g[x] - Derivative[1][g][x]/f[x])*D[w[x, y], y] == 0; 
sol =  AbsoluteTiming[TimeConstrained[DSolve[pde, w[x, y], {x, y}], 60*10]];
 

Failed

Maple ✓

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

\[w \left (x , y\right ) = \textit {\_F1} \left (\frac {\left (-y f \left (x \right )^{2}-f \left (x \right ) g \left (x \right )\right ) \left (\int \frac {\frac {d}{d x}f \left (x \right )}{f \left (x \right )^{2} g \left (x \right )}d x \right )-1}{\left (y f \left (x \right )+g \left (x \right )\right ) f \left (x \right )}\right )\]

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7.2.29.5 [793] problem number 5

problem number 793

Added Feb. 7, 2019.

Problem 2.8.6.5 from Handbook of first order partial differential equations by Polyanin, Zaitsev, Moussiaux.

Solve for \(w(x,y)\)

\[ f^2(x) w_x + \left ( f'(x) y^2 -g(x) (y-f(x)) \right ) w_y = 0 \]

Mathematica ✗

ClearAll["Global`*"]; 
pde =  f[x]^2*D[w[x, y], x] + (Derivative[1][f][x]*y^2 - g[x]*(y - f[x]))*D[w[x, y], y] == 0; 
sol =  AbsoluteTiming[TimeConstrained[DSolve[pde, w[x, y], {x, y}], 60*10]];
 

Failed

Maple ✗

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

sol=()

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7.2.29.6 [794] problem number 6

problem number 794

Added Feb. 7, 2019.

Problem 2.8.6.6 from Handbook of first order partial differential equations by Polyanin, Zaitsev, Moussiaux.

Solve for \(w(x,y)\)

\[ w_x + \left ( y^2 - \frac {f''(x)}{f(x)} \right ) w_y = 0 \]

Mathematica ✗

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

Failed

Maple ✓

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

\[w \left (x , y\right ) = \textit {\_F1} \left (\frac {\left (-y f \left (x \right )^{2}-\left (\frac {d}{d x}f \left (x \right )\right ) f \left (x \right )\right ) \left (\int \frac {1}{f \left (x \right )^{2}}d x \right )-1}{\left (y f \left (x \right )+\frac {d}{d x}f \left (x \right )\right ) f \left (x \right )}\right )\]

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7.2.29.7 [795] problem number 7

problem number 795

Added Feb. 7, 2019.

Problem 2.8.6.7 from Handbook of first order partial differential equations by Polyanin, Zaitsev, Moussiaux.

Solve for \(w(x,y)\)

\[ g(x) w_x + \left ( a f(x) g(x) y^3 + (b f(x) g^3(x) + g'(x)) y+ c f(x) g^4(x) \right ) w_y = 0 \]

Mathematica ✗

ClearAll["Global`*"]; 
pde =  g[x]*D[w[x, y], x] + (a*f[x]*g[x]*y^3 + (b*f[x]*g[x]^3 + Derivative[1][g][x])*y + c*f[x]*g[x]^4)*D[w[x, y], y] == 0; 
sol =  AbsoluteTiming[TimeConstrained[DSolve[pde, w[x, y], {x, y}], 60*10]];
 

Failed

Maple ✓

restart; 
pde :=  g(x)*diff(w(x,y),x)+(a*f(x)*g(x)*y^3 + (b*f(x)*g(x)^3 + diff(g(x),x))*y+ c*f(x)*g(x)^4)*diff(w(x,y),y) = 0; 
cpu_time := timelimit(60*10,CodeTools[Usage](assign('sol',pdsolve(pde,w(x,y)) ),output='realtime'));
 

\[w \left (x , y\right ) = \textit {\_F1} \left (\frac {b^{3} \ln \left (\frac {-\RootOf \left (a \,c^{2} \textit {\_Z}^{3}+b^{3} \textit {\_Z} -b^{3}\right ) c g \left (x \right )-b y}{c g \left (x \right )}\right )}{3 \RootOf \left (a \,c^{2} \textit {\_Z}^{3}+b^{3} \textit {\_Z} -b^{3}\right )^{2} a \,c^{2}+b^{3}}-b \left (\int f \left (x \right ) g \left (x \right )^{2}d x \right )\right )\]

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7.2.29.8 [796] problem number 8

problem number 796

Added Feb. 7, 2019.

Problem 2.8.6.8 from Handbook of first order partial differential equations by Polyanin, Zaitsev, Moussiaux.

Solve for \(w(x,y)\)

\[ w_x + \left ( f(x) y^3+3 f(x) h(x) y^2+(g(x)+3 f(x) h^2(x)) y+ f(x) h^3(x) + g(x) h(x) - h'(x) \right ) w_y = 0 \]

Mathematica ✓

ClearAll["Global`*"]; 
pde =  D[w[x, y], x] + (f[x]*y^3 + 3*f[x]*h[x]*y^2 + (g[x] + 3*f[x]*h[x]^2)*y + f[x]*h[x]^3 + g[x]*h[x] - Derivative[1][h][x])*D[w[x, y], y] == 0; 
sol =  AbsoluteTiming[TimeConstrained[DSolve[pde, w[x, y], {x, y}], 60*10]];
 

\[\left \{\left \{w(x,y)\to c_1\left (\frac {2 (h(x)+y)^2 \int _1^x\exp \left (2 \int _1^{K[2]}g(K[1])dK[1]\right ) f(K[2])dK[2]+\exp \left (2 \int _1^xg(K[1])dK[1]\right )}{(h(x)+y)^2}\right )\right \}\right \}\]

Maple ✓

restart; 
pde := diff(w(x,y),x)+(f(x)*y^3+3*f(x)*h(x)*y^2+(g(x)+3*f(x)*h(x)^2)*y+ f(x)*h(x)^3 + g(x)* h(x) - diff(h(x),x) )*diff(w(x,y),y) = 0; 
cpu_time := timelimit(60*10,CodeTools[Usage](assign('sol',pdsolve(pde,w(x,y)) ),output='realtime'));
 

\[w \left (x , y\right ) = \textit {\_F1} \left (\frac {2 \left (y +h \left (x \right )\right )^{2} \left (\int {\mathrm e}^{2 \left (\int g \left (x \right )d x \right )} f \left (x \right )d x \right )+{\mathrm e}^{2 \left (\int g \left (x \right )d x \right )}}{\left (y +h \left (x \right )\right )^{2}}\right )\]

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7.2.29.9 [797] problem number 9

problem number 797

Added Feb. 7, 2019.

Problem 2.8.6.9 from Handbook of first order partial differential equations by Polyanin, Zaitsev, Moussiaux.

Solve for \(w(x,y)\)

\[ w_x + \left ( \frac {g'(x)}{f^2(x) (a g(x) + b)^3} y^3 + \frac {f'(x)}{f(x)} y + f(x) g'(x) \right ) w_y = 0 \]

Mathematica ✗

ClearAll["Global`*"]; 
pde =  D[w[x, y], x] + ((Derivative[1][g][x]*y^3)/(f[x]^2*(a*g[x] + b)^3) + (Derivative[1][f][x]*y)/f[x] + f[x]*Derivative[1][g][x])*D[w[x, y], y] == 0; 
sol =  AbsoluteTiming[TimeConstrained[DSolve[pde, w[x, y], {x, y}], 60*10]];
 

Failed

Maple ✓

restart; 
pde := diff(w(x,y),x)+(diff(g(x),x)/(f(x)^2 *(a*g(x)+b)^3)*y^3 + diff(f(x),x)/f(x) * y + f(x)*diff(g(x),x) )*diff(w(x,y),y) = 0; 
cpu_time := timelimit(60*10,CodeTools[Usage](assign('sol',pdsolve(pde,w(x,y)) ),output='realtime'));
 

\[w \left (x , y\right ) = \textit {\_F1} \left (-\frac {a^{3} \ln \left (\frac {-\left (a g \left (x \right )+b \right ) \RootOf \left (-a^{3} \textit {\_Z} +\textit {\_Z}^{3}+a^{3}\right ) f \left (x \right )+a y}{\left (a g \left (x \right )+b \right ) f \left (x \right )}\right )}{a^{3}-3 \RootOf \left (-a^{3} \textit {\_Z} +\textit {\_Z}^{3}+a^{3}\right )^{2}}-\ln \left (a g \left (x \right )+b \right )\right )\]

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7.2.29.10 [798] problem number 10

problem number 798

Added Feb. 7, 2019.

Problem 2.8.6.10 from Handbook of first order partial differential equations by Polyanin, Zaitsev, Moussiaux.

Solve for \(w(x,y)\)

\[ w_x + \left ( (y-f(x))(y-g(x)) \left (y- \frac {a f(x)+b g(x)}{a+b} \right ) h(x) + \frac {y-g(x)}{f(x)-g(x)} f'(x) + \frac {y-f(x)}{g(x)-f(x)} g'(x) \right ) w_y = 0 \]

Mathematica ✗

ClearAll["Global`*"]; 
pde =  D[w[x, y], x] + ((y - f[x])*(y - g[x])*(y - (a*f[x] + b*g[x])/(a + b))*h[x] + ((y - g[x])*Derivative[1][f][x])/(f[x] - g[x]) + ((y - f[x])*Derivative[1][g][x])/(g[x] - f[x]))*D[w[x, y], y] == 0; 
sol =  AbsoluteTiming[TimeConstrained[DSolve[pde, w[x, y], {x, y}], 60*10]];
 

Failed

Maple ✓

restart; 
pde := diff(w(x,y),x)+((y-f(x))*(y-g(x))*(y- (a*f(x)+b*g(x))/(a+b))*h(x)+(y-g(x))/(f(x)-g(x))*diff(f(x),x)+ (y-f(x))/(g(x)-f(x))*diff(g(x),x) )*diff(w(x,y),y) = 0; 
cpu_time := timelimit(60*10,CodeTools[Usage](assign('sol',pdsolve(pde,w(x,y)) ),output='realtime'));
 

\[w \left (x , y\right ) = \textit {\_F1} \left (\frac {\left (\left (a +b \right ) b \ln \left (\frac {9 \left (a +b \right ) \left (a^{2}+a b +b^{2}\right ) \left (y -g \left (x \right )\right )}{\left (f \left (x \right )-g \left (x \right )\right ) \left (2 a +b \right )}\right )+\left (2 \left (-\frac {\left (\int f \left (x \right )^{2} h \left (x \right )d x \right )}{2}-\frac {\left (\int g \left (x \right )^{2} h \left (x \right )d x \right )}{2}+\int f \left (x \right ) g \left (x \right ) h \left (x \right )d x \right ) b +\left (a +b \right ) \ln \left (\frac {9 \left (a +b \right ) \left (a^{2}+a b +b^{2}\right ) \left (y -f \left (x \right )\right )}{\left (f \left (x \right )-g \left (x \right )\right ) \left (a +2 b \right )}\right )\right ) a -\left (a +b \right )^{2} \ln \left (\frac {9 \left (a^{2}+a b +b^{2}\right ) \left (-a f \left (x \right )-b g \left (x \right )+\left (a +b \right ) y \right )}{\left (f \left (x \right )-g \left (x \right )\right ) \left (a -b \right )}\right )\right ) \left (a^{2}+a b +b^{2}\right )}{3 \left (a +b \right )^{2} a b}\right )\]

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7.2.29.11 [799] problem number 11

problem number 799

Added Feb. 7, 2019.

Problem 2.8.6.11 from Handbook of first order partial differential equations by Polyanin, Zaitsev, Moussiaux.

Solve for \(w(x,y)\)

\[ w_x + \left ( f(x) y^2 + g'(x) y+ a f(x) e^{2 g(x)} \right ) w_y = 0 \]

Mathematica ✓

ClearAll["Global`*"]; 
pde =  D[w[x, y], x] + (f[x]*y^2 + Derivative[1][g][x]*y + a*f[x]*Exp[2*g[x]])*D[w[x, y], y] == 0; 
sol =  AbsoluteTiming[TimeConstrained[DSolve[pde, w[x, y], {x, y}, Assumptions -> a > 0], 60*10]];
 

\[\left \{\left \{w(x,y)\to c_1\left (\tan ^{-1}\left (\frac {y e^{-g(x)}}{\sqrt {a}}\right )-\sqrt {a} \int _1^xe^{g(K[1])} f(K[1])dK[1]\right )\right \}\right \}\]

Maple ✓

restart; 
pde := diff(w(x,y),x)+(f(x)*y^2 + diff(g(x),x)*y+ a*f(x)*exp(2*g(x)) )*diff(w(x,y),y) = 0; 
cpu_time := timelimit(60*10,CodeTools[Usage](assign('sol',pdsolve(pde,w(x,y)) assuming a>0 ),output='realtime'));
 

\[w \left (x , y\right ) = \textit {\_F1} \left (\sqrt {a}\, \left (\int {\mathrm e}^{g \left (x \right )} f \left (x \right )d x \right )-\arctan \left (\frac {y \,{\mathrm e}^{-g \left (x \right )}}{\sqrt {a}}\right )\right )\]

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7.2.29.12 [800] problem number 12

problem number 800

Added Feb. 7, 2019.

Problem 2.8.6.12 from Handbook of first order partial differential equations by Polyanin, Zaitsev, Moussiaux.

Solve for \(w(x,y)\)

\[ w_x + \left ( f'(x) y^2+ a e^{\lambda x} f(x) y+a e^{\lambda x} \right ) w_y = 0 \]

Mathematica ✗

ClearAll["Global`*"]; 
pde =  D[w[x, y], x] + (Derivative[1][f][x]*y^2 + a*Exp[lambda*x]*f[x]*y + a*Exp[lambda*x])*D[w[x, y], y] == 0; 
sol =  AbsoluteTiming[TimeConstrained[DSolve[pde, w[x, y], {x, y}], 60*10]];
 

Failed

Maple ✓

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

\[w \left (x , y\right ) = \textit {\_F1} \left (\frac {-y \left (\int \frac {\left (\frac {d}{d x}f \left (x \right )\right ) {\mathrm e}^{a \left (\int {\mathrm e}^{\lambda x} f \left (x \right )d x \right )}}{f \left (x \right )^{2}}d x \right ) f \left (x \right )-{\mathrm e}^{-\left (\int \frac {-a \,{\mathrm e}^{\lambda x} f \left (x \right )^{2}+2 \frac {d}{d x}f \left (x \right )}{f \left (x \right )}d x \right )} f \left (x \right )-\left (\int \frac {\left (\frac {d}{d x}f \left (x \right )\right ) {\mathrm e}^{a \left (\int {\mathrm e}^{\lambda x} f \left (x \right )d x \right )}}{f \left (x \right )^{2}}d x \right )}{y f \left (x \right )+1}\right )\]

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