22．(本小题满分12分)

　解：(1)在中，，

　，…………………………1分

　　 ．

　又，

　．…………………………2分

　又，

　．·································································································· 3分

　．································································································· 4分

　．············································································································ 5分

　即，所以．····························································································· 7分

　(2)当满足关系式时，函数关系式仍然成立．···················· 8分

　此时，．·············································································· 9分

　又，

　．·································································································· 10分

　又仍然成立．················································ 11分

　从而(1)中函数关系式成立．··········································································· 12分

21．(本小题满分12分)

　解：(1)当点运动到与点关于直径对称时，如图所示，此时于，

又为的直径，

　．

　，

　．

　又，

　．…………………4分

　在和中，

　，

　，

　．······················································································· 6分

　．··························································· 8分

　(2)因为点在弧上运动过程中，有，

　所以最大时，取到最大值．············································································· 10分

　当过圆心，即取最大值5时，最大，最大为．···························· 12分

20．(本小题满分10分)

　解：的形状是等腰直角三角形．····································································· 1分

　证明：连接，由题意得：

　．

　………………2分

　又，

　．

　．

　．······························································································ 5分

．············································································· 7分

　又，

　．

　．··········································································································· 9分

　所以的形状是等腰直角三角形．····································································· 10分

19．(本小题满分10分)

　解：设去年5月份汽油价格为元/升，则今年5月份的汽油价格为元/升，··········· 1分

　根据题意，得．············································································· 5分

　整理，得．

　解这个方程，得．······························································································· 8分

　经检验，是原方程的解．····················································································· 9分

　所以．

　答：今年5月份的汽油价格为元/升．····································································· 10分

18．(本小题满分10分)

　解：(1)甲、乙、丙的民主评议得分分别为：50分，80分，70分．···························· 3分

　(2)甲的平均成绩为：(分)，

　　乙的平均成绩为：(分)，

丙的平均成绩为：(分)．

由于，所以候选人乙将被录用．············································· 6分

(3)如果将笔试、面试、民主评议三项测试得分按的比例确定个人成绩，那么

甲的个人成绩为：(分)，

乙的个人成绩为：(分)，

丙的个人成绩为：(分)，

由于丙的个人成绩最高，所以候选人丙将被录用．················································ 10分

17．(本小题满分6分)

　　 解：解不等式，得，····································································· 2分

　解不等式，得．···································································· 4分

　所以，原不等式组的解集是．···································································· 5分

　在数轴上表示为

·································· 6分

14．①②③⑤　15．　16．

9．　 10．　 　11．　12．6　13．

3．如果考生在解答的中间过程出现计算错误，但并没有改变试题的实质和难度，其后续部分酌情给分，但最多不超过正确解答分数的一半；若出现严重的逻辑错误，后续部分就不再给分．

2．解答题每小题的解答中所对应的分数，是指考生正确解答到该步骤所应得的累计分数，每小题只给出一种解法，对考生的其他解法，请参照评分意见进行评分．