Réponses

2012-06-05T18:02:02+02:00

g=fof=f(f(x,y)) = f(x²-y,x²+y²) = ( (x²-y)²-x²-y²,(x²-y)²+(x²+y²)² )

g = ( x⁴- 2x²y - x² , 2x⁴ + 2x²y² + y⁴- 2x²y + y² )