deTaylor

[salvomic]

thank you!

please help to control with an differential equation still not solvable in Prime (but now ok in XCas):
y'=(x+y)^2
Is it correct to input
deTaylor((x+y)^2, [x,y], [0,0], 7) ?

I get (17/315)x^7+(2/15)x^5+(⅓)x^3
The general solution of equation (XCas) is TAN(x-c)-x
With Taylor I've taylor(TAN(x)-x), x, 6) = (⅓)x^3+(2/15)x^5+x^7+o(x)
It should be ok, isn't it?

Salvo