《高中數(shù)學(xué) 第三章 導(dǎo)數(shù)應(yīng)用 3.1 函數(shù)的單調(diào)性與極值 3.1.2.2 函數(shù)極值的應(yīng)用課件 北師大版選修22》由會(huì)員分享，可在線閱讀，更多相關(guān)《高中數(shù)學(xué) 第三章 導(dǎo)數(shù)應(yīng)用 3.1 函數(shù)的單調(diào)性與極值 3.1.2.2 函數(shù)極值的應(yīng)用課件 北師大版選修22（17頁珍藏版）》請(qǐng)?jiān)谘b配圖網(wǎng)上搜索。

1、第2 2課時(shí)函數(shù)極值的應(yīng)用MUBIAODAOHANG目標(biāo)導(dǎo)航DIANLI TOUXI典例透析SUITANGYANLIAN隨堂演練ZHISHI SHULI知識(shí)梳理目標(biāo)導(dǎo)航DIANLITOUXI典例透析SUITANGYANLIAN隨堂演練ZHISHISHULI知識(shí)梳理目標(biāo)導(dǎo)航DIANLITOUXI典例透析SUITANGYANLIAN隨堂演練ZHISHISHULI知識(shí)梳理目標(biāo)導(dǎo)航DIANLITOUXI典例透析SUITANGYANLIAN隨堂演練ZHISHISHULI知識(shí)梳理目標(biāo)導(dǎo)航DIANLITOUXI典例透析SUITANGYANLIAN隨堂演練ZHISHISHULI知識(shí)梳理1.鞏固求函數(shù)極值的方法

2、.2.利用極值判斷函數(shù)零點(diǎn)的個(gè)數(shù)或方程解的個(gè)數(shù).3.根據(jù)方程解的個(gè)數(shù)求參數(shù)的取值范圍.MUBIAODAOHANG目標(biāo)導(dǎo)航DIANLI TOUXI典例透析SUITANGYANLIAN隨堂演練ZHISHI SHULI知識(shí)梳理目標(biāo)導(dǎo)航DIANLITOUXI典例透析SUITANGYANLIAN隨堂演練ZHISHISHULI知識(shí)梳理目標(biāo)導(dǎo)航DIANLITOUXI典例透析SUITANGYANLIAN隨堂演練ZHISHISHULI知識(shí)梳理目標(biāo)導(dǎo)航DIANLITOUXI典例透析SUITANGYANLIAN隨堂演練ZHISHISHULI知識(shí)梳理目標(biāo)導(dǎo)航DIANLITOUXI典例透析SUITANGYANLIAN隨

3、堂演練ZHISHISHULI知識(shí)梳理若f(x0)=0,且函數(shù)f(x)在x0的左側(cè)是增加(減少)的,在x0的右側(cè)是減少(增加)的,則函數(shù)f(x)在x=x0處取得極大(小)值.MUBIAODAOHANG目標(biāo)導(dǎo)航DIANLI TOUXI典例透析SUITANGYANLIAN隨堂演練ZHISHI SHULI知識(shí)梳理目標(biāo)導(dǎo)航DIANLITOUXI典例透析SUITANGYANLIAN隨堂演練ZHISHISHULI知識(shí)梳理目標(biāo)導(dǎo)航DIANLITOUXI典例透析SUITANGYANLIAN隨堂演練ZHISHISHULI知識(shí)梳理目標(biāo)導(dǎo)航DIANLITOUXI典例透析SUITANGYANLIAN隨堂演練ZHISHI

4、SHULI知識(shí)梳理目標(biāo)導(dǎo)航DIANLITOUXI典例透析SUITANGYANLIAN隨堂演練ZHISHISHULI知識(shí)梳理題型一題型二MUBIAODAOHANG目標(biāo)導(dǎo)航DIANLI TOUXI典例透析SUITANGYANLIAN隨堂演練ZHISHI SHULI知識(shí)梳理目標(biāo)導(dǎo)航DIANLITOUXI典例透析SUITANGYANLIAN隨堂演練ZHISHISHULI知識(shí)梳理目標(biāo)導(dǎo)航DIANLITOUXI典例透析SUITANGYANLIAN隨堂演練ZHISHISHULI知識(shí)梳理目標(biāo)導(dǎo)航DIANLITOUXI典例透析SUITANGYANLIAN隨堂演練ZHISHISHULI知識(shí)梳理目標(biāo)導(dǎo)航DIANLI

5、TOUXI典例透析SUITANGYANLIAN隨堂演練ZHISHISHULI知識(shí)梳理題型一題型二MUBIAODAOHANG目標(biāo)導(dǎo)航DIANLI TOUXI典例透析SUITANGYANLIAN隨堂演練ZHISHI SHULI知識(shí)梳理目標(biāo)導(dǎo)航DIANLITOUXI典例透析SUITANGYANLIAN隨堂演練ZHISHISHULI知識(shí)梳理目標(biāo)導(dǎo)航DIANLITOUXI典例透析SUITANGYANLIAN隨堂演練ZHISHISHULI知識(shí)梳理目標(biāo)導(dǎo)航DIANLITOUXI典例透析SUITANGYANLIAN隨堂演練ZHISHISHULI知識(shí)梳理目標(biāo)導(dǎo)航DIANLITOUXI典例透析SUITANGYAN

6、LIAN隨堂演練ZHISHISHULI知識(shí)梳理題型一題型二反思反思用求導(dǎo)的方法確定方程解的個(gè)數(shù),是一種很有效的方法.它通過函數(shù)的變化情況,運(yùn)用數(shù)形結(jié)合思想來確定函數(shù)圖像與x軸的交點(diǎn)個(gè)數(shù),從而判斷方程解的個(gè)數(shù).MUBIAODAOHANG目標(biāo)導(dǎo)航DIANLI TOUXI典例透析SUITANGYANLIAN隨堂演練ZHISHI SHULI知識(shí)梳理目標(biāo)導(dǎo)航DIANLITOUXI典例透析SUITANGYANLIAN隨堂演練ZHISHISHULI知識(shí)梳理目標(biāo)導(dǎo)航DIANLITOUXI典例透析SUITANGYANLIAN隨堂演練ZHISHISHULI知識(shí)梳理目標(biāo)導(dǎo)航DIANLITOUXI典例透析SUITAN

7、GYANLIAN隨堂演練ZHISHISHULI知識(shí)梳理目標(biāo)導(dǎo)航DIANLITOUXI典例透析SUITANGYANLIAN隨堂演練ZHISHISHULI知識(shí)梳理題型一題型二MUBIAODAOHANG目標(biāo)導(dǎo)航DIANLI TOUXI典例透析SUITANGYANLIAN隨堂演練ZHISHI SHULI知識(shí)梳理目標(biāo)導(dǎo)航DIANLITOUXI典例透析SUITANGYANLIAN隨堂演練ZHISHISHULI知識(shí)梳理目標(biāo)導(dǎo)航DIANLITOUXI典例透析SUITANGYANLIAN隨堂演練ZHISHISHULI知識(shí)梳理目標(biāo)導(dǎo)航DIANLITOUXI典例透析SUITANGYANLIAN隨堂演練ZHISHIS

8、HULI知識(shí)梳理目標(biāo)導(dǎo)航DIANLITOUXI典例透析SUITANGYANLIAN隨堂演練ZHISHISHULI知識(shí)梳理題型一題型二【例2】 已知函數(shù)f(x)=x3-x2-x+a,(1)求函數(shù)f(x)的極值;(2)若函數(shù)f(x)的圖像與x軸有且僅有一個(gè)交點(diǎn),求實(shí)數(shù)a的取值范圍.分析:第(1)小題考查函數(shù)極值的概念及求法,注意說明函數(shù)的極值為極大值還是極小值.第(2)小題主要考查函數(shù)的極值、單調(diào)性及圖像與x軸交點(diǎn)的情況,可用數(shù)形結(jié)合的方法分析得出.MUBIAODAOHANG目標(biāo)導(dǎo)航DIANLI TOUXI典例透析SUITANGYANLIAN隨堂演練ZHISHI SHULI知識(shí)梳理目標(biāo)導(dǎo)航DIAN

9、LITOUXI典例透析SUITANGYANLIAN隨堂演練ZHISHISHULI知識(shí)梳理目標(biāo)導(dǎo)航DIANLITOUXI典例透析SUITANGYANLIAN隨堂演練ZHISHISHULI知識(shí)梳理目標(biāo)導(dǎo)航DIANLITOUXI典例透析SUITANGYANLIAN隨堂演練ZHISHISHULI知識(shí)梳理目標(biāo)導(dǎo)航DIANLITOUXI典例透析SUITANGYANLIAN隨堂演練ZHISHISHULI知識(shí)梳理題型一題型二MUBIAODAOHANG目標(biāo)導(dǎo)航DIANLI TOUXI典例透析SUITANGYANLIAN隨堂演練ZHISHI SHULI知識(shí)梳理目標(biāo)導(dǎo)航DIANLITOUXI典例透析SUITANGY

10、ANLIAN隨堂演練ZHISHISHULI知識(shí)梳理目標(biāo)導(dǎo)航DIANLITOUXI典例透析SUITANGYANLIAN隨堂演練ZHISHISHULI知識(shí)梳理目標(biāo)導(dǎo)航DIANLITOUXI典例透析SUITANGYANLIAN隨堂演練ZHISHISHULI知識(shí)梳理目標(biāo)導(dǎo)航DIANLITOUXI典例透析SUITANGYANLIAN隨堂演練ZHISHISHULI知識(shí)梳理題型一題型二反思注意求極值的步驟及數(shù)形結(jié)合方法的應(yīng)用. MUBIAODAOHANG目標(biāo)導(dǎo)航DIANLI TOUXI典例透析SUITANGYANLIAN隨堂演練ZHISHI SHULI知識(shí)梳理目標(biāo)導(dǎo)航DIANLITOUXI典例透析SUITA

11、NGYANLIAN隨堂演練ZHISHISHULI知識(shí)梳理目標(biāo)導(dǎo)航DIANLITOUXI典例透析SUITANGYANLIAN隨堂演練ZHISHISHULI知識(shí)梳理目標(biāo)導(dǎo)航DIANLITOUXI典例透析SUITANGYANLIAN隨堂演練ZHISHISHULI知識(shí)梳理目標(biāo)導(dǎo)航DIANLITOUXI典例透析SUITANGYANLIAN隨堂演練ZHISHISHULI知識(shí)梳理題型一題型二MUBIAODAOHANG目標(biāo)導(dǎo)航DIANLI TOUXI典例透析SUITANGYANLIAN隨堂演練ZHISHI SHULI知識(shí)梳理目標(biāo)導(dǎo)航DIANLITOUXI典例透析SUITANGYANLIAN隨堂演練ZHISHI

12、SHULI知識(shí)梳理目標(biāo)導(dǎo)航DIANLITOUXI典例透析SUITANGYANLIAN隨堂演練ZHISHISHULI知識(shí)梳理目標(biāo)導(dǎo)航DIANLITOUXI典例透析SUITANGYANLIAN隨堂演練ZHISHISHULI知識(shí)梳理目標(biāo)導(dǎo)航DIANLITOUXI典例透析SUITANGYANLIAN隨堂演練ZHISHISHULI知識(shí)梳理題型一題型二MUBIAODAOHANG目標(biāo)導(dǎo)航DIANLI TOUXI典例透析SUITANGYANLIAN隨堂演練ZHISHI SHULI知識(shí)梳理目標(biāo)導(dǎo)航DIANLITOUXI典例透析SUITANGYANLIAN隨堂演練ZHISHISHULI知識(shí)梳理目標(biāo)導(dǎo)航DIANLI

13、TOUXI典例透析SUITANGYANLIAN隨堂演練ZHISHISHULI知識(shí)梳理目標(biāo)導(dǎo)航DIANLITOUXI典例透析SUITANGYANLIAN隨堂演練ZHISHISHULI知識(shí)梳理目標(biāo)導(dǎo)航DIANLITOUXI典例透析SUITANGYANLIAN隨堂演練ZHISHISHULI知識(shí)梳理1 2 3 41.已知函數(shù)f(x)=x3-3x2-9x,則在區(qū)間(-2,2)內(nèi),f(x)的零點(diǎn)個(gè)數(shù)為()A.0B.1C.2D.3解析:由f(x)=3x2-6x-9=0,得x=-1或x=3.易知f(x)在(-2,-1)上是增加的,在(-1,2)上是減少的,又f(-2)=-2,f(-1)=5,f(2)=-22,

14、所以函數(shù)f(x)在(-2,2)內(nèi)有2個(gè)零點(diǎn).答案:CMUBIAODAOHANG目標(biāo)導(dǎo)航DIANLI TOUXI典例透析SUITANGYANLIAN隨堂演練ZHISHI SHULI知識(shí)梳理目標(biāo)導(dǎo)航DIANLITOUXI典例透析SUITANGYANLIAN隨堂演練ZHISHISHULI知識(shí)梳理目標(biāo)導(dǎo)航DIANLITOUXI典例透析SUITANGYANLIAN隨堂演練ZHISHISHULI知識(shí)梳理目標(biāo)導(dǎo)航DIANLITOUXI典例透析SUITANGYANLIAN隨堂演練ZHISHISHULI知識(shí)梳理目標(biāo)導(dǎo)航DIANLITOUXI典例透析SUITANGYANLIAN隨堂演練ZHISHISHULI知識(shí)梳

15、理1 2 3 4答案:B MUBIAODAOHANG目標(biāo)導(dǎo)航DIANLI TOUXI典例透析SUITANGYANLIAN隨堂演練ZHISHI SHULI知識(shí)梳理目標(biāo)導(dǎo)航DIANLITOUXI典例透析SUITANGYANLIAN隨堂演練ZHISHISHULI知識(shí)梳理目標(biāo)導(dǎo)航DIANLITOUXI典例透析SUITANGYANLIAN隨堂演練ZHISHISHULI知識(shí)梳理目標(biāo)導(dǎo)航DIANLITOUXI典例透析SUITANGYANLIAN隨堂演練ZHISHISHULI知識(shí)梳理目標(biāo)導(dǎo)航DIANLITOUXI典例透析SUITANGYANLIAN隨堂演練ZHISHISHULI知識(shí)梳理1 2 3 43已知直線

16、y=a與函數(shù)y=x3-3x的圖像有三個(gè)不同的交點(diǎn),則a的取值范圍是. 解析:f(x)=3x2-3.令f(x)=0可以得到x=1或x=-1.f(1)=-2,f(-1)=2,-2a2.答案:(-2,2)MUBIAODAOHANG目標(biāo)導(dǎo)航DIANLI TOUXI典例透析SUITANGYANLIAN隨堂演練ZHISHI SHULI知識(shí)梳理目標(biāo)導(dǎo)航DIANLITOUXI典例透析SUITANGYANLIAN隨堂演練ZHISHISHULI知識(shí)梳理目標(biāo)導(dǎo)航DIANLITOUXI典例透析SUITANGYANLIAN隨堂演練ZHISHISHULI知識(shí)梳理目標(biāo)導(dǎo)航DIANLITOUXI典例透析SUITANGYANL

17、IAN隨堂演練ZHISHISHULI知識(shí)梳理目標(biāo)導(dǎo)航DIANLITOUXI典例透析SUITANGYANLIAN隨堂演練ZHISHISHULI知識(shí)梳理1 2 3 44已知a為實(shí)數(shù),函數(shù)f(x)=-x3+3x+a.(1)求f(x)的極值;(2)求當(dāng)a為何值時(shí),方程f(x)=0恰好有兩個(gè)實(shí)數(shù)根?解:(1)令f(x)=-3x2+3=0,得x=-1或x=1.因?yàn)楫?dāng)x(-,-1)時(shí),f(x)0;當(dāng)x(1,+)時(shí),f(x)a-2,即函數(shù)的極大值大于極小值,所以當(dāng)極大值等于0,極小值小于0時(shí),曲線f(x)與x軸恰有兩個(gè)交點(diǎn),所以方程f(x)=0恰好有兩個(gè)實(shí)數(shù)根,a+2=0,即a=-2,如圖.當(dāng)極小值等于0,極大值大于0時(shí),曲線f(x)與x軸恰有兩個(gè)交點(diǎn),即方程f(x)=0恰好有兩個(gè)實(shí)數(shù)根,所以a-2=0,即a=2.如圖.綜上,當(dāng)a=2或a=-2時(shí),方程恰有兩個(gè)實(shí)數(shù)根.