method of characteristic !!!

(Rofl) Hi everyone,

i have a problem for solving a partial differential equation with the method of characteristic. I already spent lot of time and I have not yet found the solution

http://latex.codecogs.com/gif.latex?...+y^2, x>0, y>0

http://latex.codecogs.com/gif.latex?u(x,1)=\sqrt{x^2+1}

In fact, when I try to solve du/dt after I already obtained before dx/dt and dy/dt, I have an expression an expression which depends on t and u. Impossible to solve...

If someone can help me pleasseeeee!!!!

Thankss ;)

Re: method of characteristic

hi,

I advanced in my problem but I'm again in trouble

I transformed my expression with polar coordinates

so (c is my constant)

Now I have to find the value of my constant by caracteristics method

so I continue my reasoning:

such as

such as

we find before that

moreover with my initial condition

so i guess

for t=0,

donc que

so

in short I feel that's wrong

someone can help me please??

thanks:)