x | … | -2 | -
| -1 | -
| 0 |
| 1 |
| 2 | … | ||||||||
y | … | 7 | -
| -2 | -
| -1 | -
| -2 | -
| 7 | … |
![](http://hiphotos.baidu.com/zhidao/pic/item/6a63f6246b600c33fb132179194c510fd9f9a11d.jpg)
②函數(shù)圖象關(guān)于y軸對(duì)稱(chēng);
函數(shù)圖象有兩個(gè)最低點(diǎn);
當(dāng)-1≤x≤0或x≥1時(shí),y隨x的增大而增大;
當(dāng)0≤x≤1或x≤-1時(shí),y隨x的增大而減??;
函數(shù)圖象與x軸有兩個(gè)公共點(diǎn).
③y=(x2-1)2-2,
當(dāng)x2-1=0時(shí),即x=±1時(shí),函數(shù)y有最小值-2.
(2)當(dāng)k=-2或k>-1時(shí),平行于x軸的直線與 函數(shù)y=x4-2x2-1的圖象有2個(gè)公共點(diǎn);
當(dāng)k=-1時(shí),平行于x軸的直線與函數(shù)y=x4-2x2-1的圖象有3個(gè)公共點(diǎn);
當(dāng)-2<k<-1時(shí),平行于x軸的直線與函數(shù)y=x4-2x2-1的圖象有4個(gè)公共點(diǎn).