Hi,

    i meet  a partial differential equation seems not complicated

with(PDEtools):

PDE := (diff(f(x__1, x__2, p__1, p__2), x__1))*p__1/m-(diff(f(x__1, x__2, p__1, p__2), p__1))*(2*k*x__1-k*x__2)+(diff(f(x__1, x__2, p__1, p__2), x__2))*p__2/m-(diff(f(x__1, x__2, p__1, p__2), p__2))*(-k*x__1+2*k*x__2);

when i use

     pdsolve(PDE);

i get nothing,but i sure

    f=c*(p__1^2/m+p__2^2/m+4*p__1*p__2/m+6*k*x__1*x__2) 

is the one solution of the differential equation .

how i can get solutions about of the above equation.

thanks .

 when i  input  bellow

• Maple can output

hi, the equations read as 

eq:=[2*x-0.2e-1*y-2.04*sqrt(-v^2+1)*v, 2*y-0.2e-1*x-2.16*sqrt(-u^2+1)*u, 2*u+2.16*u^2*y/sqrt(-u^2+1)-2.16*sqrt(-u^2+1)*y, 2*v+2.04*v^2*x/sqrt(-v^2+1)-2.04*sqrt(-v^2+1)*x] ;

i do as follows using DirectSearch package v.2

i find the solutions not the same,some time the results not much difference,but another,sols1 have one solution,sols2 have three solutions.in some time,some solutions are lost，the result show  me  random.may i have run the command serveral times? regards.

I want to  get   nonlinear equations solutions using 'solve',but i always meet that the program running long long time,i want to stop this 'solve' procedure giving a limit time.how do i.can you help me.thanks a lot.

eq:=[Vector[row](4, {(1) = 0., (2) = 0., (3) = 0., (4) = 0.}), Vector[row](4, {(1) = -0.3381778526e-2, (2) = -.3381778526, (3) = -.3185010532, (4) = 0.}), Vector[row](4, {(1) = 0., (2) = 0., (3) = 0., (4) = 0.}), Vector[row](4, {(1) = 0., (2) = 0., (3) = 0., (4) = 0.}), Vector[row](4, {(1) = 0., (2) = 0., (3) = 0., (4) = 0.})]

how i can get a unique results:[Vector[row](4, {(1) = 0., (2) = 0., (3) = 0., (4) = 0.}), Vector[row](4, {(1) = -0.3381778526e-2, (2) = -.3381778526, (3) = -.3185010532, (4) = 0.})]