设Y1=K1(X+2),Y2=K2/X
Y=K1(X+2)-K2/X
代入X=1,Y=0
3K1-K2=0
代入X=4,Y=7
6K1-K2/4=7
7K2/4=7
K2=4
代入,K1=4/3
所以Y=4/3(X+2)-4/X=4X/3+8/3-4/X
(2)代入X=2,
Y=8/3+8/3-2=10/3
设Y1=K1(X+2),Y2=K2/X
Y=K1(X+2)-K2/X
代入X=1,Y=0
3K1-K2=0
代入X=4,Y=7
6K1-K2/4=7
7K2/4=7
K2=4
代入,K1=4/3
所以Y=4/3(X+2)-4/X=4X/3+8/3-4/X
(2)代入X=2,
Y=8/3+8/3-2=10/3