苯鸟CD
幼苗
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c=1,F(1,0),设M(2cost,√3sint),
w=3MP+4MF=3√[(2cost-1)^2+(√3sint+1)^2]+4√[(2cost-1)^2+(√3sint)^2]
=3√[(cost)^2-4cost+2√3sint+5]+4√[(cost)^2-4cost+4]
设u=2-cost,则cost=2-u,(sint)^2=1-(2-u)^2=-3+4u-u^2,
w=3√[u^2+1土2√(-9+12u-3u^2)]+4u(1
1年前
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