2.1.36 \(a u_x+b u_y=0\) Problem 3.3(b) Lokenath Debnath

problem number 36

Added June 2, 2019.

Problem 3.3(b) nonlinear pde’s by Lokenath Debnath, 3rd edition.

Solve for \(u(x,y)\) \[ a u_x+b u_y=0 \]

Mathematica

ClearAll["Global`*"]; 
pde =  a*D[u[x, y], x] + b*D[u[x, y], y] ==0; 
sol =  AbsoluteTiming[TimeConstrained[DSolve[pde ,u[x, y], {x, y}], 60*10]];
 

\[\left \{\left \{u(x,y)\to c_1\left (y-\frac {b x}{a}\right )\right \}\right \}\]

Maple

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

\[u \left (x , y\right ) = \mathit {\_F1} \left (\frac {y a -b x}{a}\right )\]

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