On Friday, 8 January 2021 at 10:36:30 UTC+11, drhu...@gmail.com wrote:
On Thursday, 7 January 2021 at 23:45:38 UTC+11, drhu...@gmail.com wrote:
On Thursday, 7 January 2021 at 23:28:50 UTC+11, drhu...@gmail.com wrote:
On Thursday, 7 January 2021 at 13:30:51 UTC+11, Nasser M. Abbasi wrote:
why wolfram cannot find simple solution in many equations? many examples, e.g.:
1/x*y"-y-x^2=0
1/x*y"-y-x^3=0
1/x*y"-y-x^4=0
......
mathHand.com can: http://server.drhuang.com/input/?guess=dsolve%281%2Fx*ds%28y%2Cx%2C2%29-y-x%5E3%29
so it is good idea to use two software to check solution.
For the first ode above. This is inhomogeneous Airy ode. The solution you give for
1/x*y''[x]-y[x]-x^2==0
is
y(x)= -6+Ai(x)*C1+Bi(x)*C2-x^3
But this solution is not verified by Maple:
==============
restart;
ode := 1/x*diff(y(x),x$2) - y(x) - x^2 = 0;
sol := y(x) = -6+AiryAi(x)*_C2 + AiryBi(x)*_C1-x^3;
odetest(sol,ode);
x^3 - x^2
=================
Which is not zero. Hence not a valid solution?
input your equation into mathHand.com, click the "dsolve" button to solve, then click the "test" button to test its solution, or click the "to inte" button to plot if it did not auto plot.--Nasserthe bug fixed. thanks.
mathHand.com
http://mathHand.comwolfram gives very complicated solution:
y"-x y-x^3+2=0
mathHand.com gives very simple solution: http://server.drhuang.com/input/?guess=dsolve%28ds%28y%2Cx%2C2%29-x*y-x%5E3%2B2%29
wolfram gives very complicated solution:
y"-x y'-x y-x^3+2=0
mathHand.com gives very simple solution: http://server.drhuang.com/input/?guess=dsolve%28ds%28y%2Cx%2C2%29-ds%28y%2Cx%2C1%29*x-y*x-x%5E3%2B2%29&inp=ds%28y%2Cx%2C2%29-ds%28y%2Cx%2C1%29*x-y*x-x%5E3%2B2
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