初中数学精通者请进来回答此题(空着的)
解:
x²+y²=(3-x)²=9-6x+x²=========>9-y²=6x
黄色△相似
x/EC=y/CF=(3-x)/EF
∴(x+y+3-x)/(EC+CF+EF)=x/EC=x/(3-y)
∴(EC+CF+EF)x=(y+3)(3-y)=9-y²=6x
∴EC+CF+EF=6
热门标签:
解:
x²+y²=(3-x)²=9-6x+x²=========>9-y²=6x
黄色△相似
x/EC=y/CF=(3-x)/EF
∴(x+y+3-x)/(EC+CF+EF)=x/EC=x/(3-y)
∴(EC+CF+EF)x=(y+3)(3-y)=9-y²=6x
∴EC+CF+EF=6