最新点击解决最值问题的常用方法.doc

点击解决最值问题的常用方法
several group number, then with b ± a, =c,c is is methyl b two vertical box between of accurate s的最小值为_______。
解析：配方得
原式=2〔x2－2xy+y2〕+x2+2x+4
=4〔x－y〕2+〔x+1〕2+3
显见，当x=－1，y=－1时，原式有最小值3。
二、分类讨论法
当解决的问题存在一些不确定因素，这时常用分类讨论法按一定的标准或原那么分为假设干类、
several group number, then with b ± a, =c,c is is methyl b two vertical box between of accurate size. Per-2~3 measurement, such as proceeds of c values are equal and equal to the design value, then the vertical installation accurate. For example a, b, and c valueswhile on horizontal vertical errors for measurement, General in iron angle code bit at measurement level points grid errors, specific method is from baseline to methyl vertical box center line distance for a,, to b vertical box distance for b, list can measured
several group number, then with b ± a, =c,c is is methyl b two vertical box between of accurate size. Per-2~3 measurement, such as proceeds of c values are equal and equal to the design value, then the vertical installation accurate. For example a, b, and c valueswhile on horizontal vertical errors for measurement, General in iron angle code bit at measurement level points grid errors, specific method is from baseline to methyl vertical box center line distance for a,, to b vertical box distance for b, list can measured3
several group number, then with b ± a, =c,c is is methyl b two vertical box between of accurate size. Per-2~3 measurement, such as proceeds of c values are equal and equal to the design value, then the vertical installation accurate. For example a, b, and c valueswhile on horizontal vertical errors for measurement, General in iron angle code bit at measurement level points grid errors, specific method is from baseline to methyl vertical box center line distance for a,, to b vertical box distance for b, list can measured
然后逐类求解，再综合这几点的结论从而求解。
例2 0≤a≤4，那么的最大值等于〔 〕
〔A〕1 〔B〕5 〔C〕8 〔D〕3
解析：根据条件采用取零点分段讨论法求最大值。
根据绝对值的几何意义，a=2 , a=3是两个零点，结合0≤a≤4分成0≤a≤2，2＜a