m=-3/2
k=-1/4
y=(x-3/2)的平方-1/4
當(dāng)y=0時
(x-3/2)²-1/4=0
x-3/2=-1/2 或x-3/2=1/2
x=1或x=2
圖像與X軸的交點(diǎn)坐標(biāo)(1,0) 、（2,0）x-3/2=-1/2 或x-3/2=1/2(x-3/2)²-1/4=0(x-3/2)²=1/4直接開平方啊，就得x-3/2=-1/2 或x-3/2=1/2當(dāng)X為何值時，Y＞0，=0，＜0？當(dāng)x<1或x>2時y>0當(dāng)x=1或x=2時y=0當(dāng)1