#249 desolve(diff(y(x),x)=(4-2*x)/(3*y^2-5),y(x)); WRONG

closed
nobody
None
5
2003-04-08
2003-03-11
Anonymous
No

(C4) desolve(diff(y(x),x)=(4-2*x)/(3*y^2-5),y(x));

                2

                   x     4 x

(D4) y(x) = - -------- + -------- + y(0)

                   2      2

                3 y  - 5   3 y  - 5

it should be

                2

                   x     4 x

(D4) y(x) = - -------- + -------- + y(0)

                   2      2

                  y  - 5     y  - 5

Discussion

  • Logged In: YES
    user_id=588346

    This is not a bug in desolve. As the documentation says,
    desolve requires functional dependencies to be explicit --
    there is no connection between the function y(x) and the
    variable y. It turns out that desolve can't solve this equation,
    but ode2 claims to. I don't know if its solution is correct.

     
    • status: open --> closed