當(dāng)t大于等于x小于等于t+1時(shí),求函數(shù)y=2分之1x平方-x-2分之5的最小值

數(shù)學(xué)人氣：821 ℃時(shí)間：2019-08-20 06:05:25

優(yōu)質(zhì)解答

先對(duì)方程配方,得對(duì)稱軸為x =1,在分類討論
1,題中所給范圍在對(duì)稱軸的左側(cè),在對(duì)稱軸左側(cè)函數(shù)為減函數(shù),當(dāng) x=t+1時(shí)取最小
2,題中所給范圍在對(duì)稱軸的右側(cè),在對(duì)稱軸右側(cè)函數(shù)為增函數(shù),當(dāng) x=t時(shí)取最小
3,對(duì)稱軸在題中所給范圍中,最小值極為頂點(diǎn)縱坐標(biāo)點(diǎn)