易知,（x²/2)+(y²/3)≤1.可设x=(r√2)cost,y=(r√3)sint.(t,r∈R,0≤r≤1).∴P=2x+y=r[(2√2)cost+(√3)sint]=(r√11)sin(t+m)≤√11.∴Pmax=√11.