设Y1=K1X
Y2=K2(x-1)
则y=k1x+k2(x-1)
当x=3时y=3k1+2k2 =4
当 x=1时y=k1=2
(计算过程不必写出:3k1=6 K1=2 6+2k2=4 2k2=-2 k2=-1)
解得K1=2 K2=-1
所以Y1=2X
Y2=-X+1
设Y1=K1X
Y2=K2(x-1)
则y=k1x+k2(x-1)
当x=3时y=3k1+2k2 =4
当 x=1时y=k1=2
(计算过程不必写出:3k1=6 K1=2 6+2k2=4 2k2=-2 k2=-1)
解得K1=2 K2=-1
所以Y1=2X
Y2=-X+1