(2) 作AB的中点E,AE=AB÷2=4÷2=2 ∵A=(0,4),∴E=A+AE=(0,4)+2=(2,4) E’=Ek=(2,4)×(3,0.5)=(2×3-4×0.5,4×3+2×0.5)=(6-2,12+1)=(4,13) (3)设A’B’的解析式为y=kx+b 则b-2k=12,10k+b=14 解得k=1/6 b=37/3 ∴y=(x+74)/6 当x=0时 y=74/6=37/3 ∴DF=37/3 作A’G⊥FD于G,则AG=2 ∴S△A’FD=37/3*2/2=37/3 (4) F=(0,37/3) H=F/k=(0,37/3)÷(3,0.5)=(0+37/6,37-0)÷(9+0.25) =(37/6,37)÷(37/4) =[(37/6)×(4/37),37×(4/37)] =(2/3,4)
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