大丰市第二中学高二年级数学周练第1次周练2008年9月7日命题：陈建圣一、填空题（14×5=70）1．已知△ABC中，，则；2．在△ABC中，若，则；3．若钝角三角形三个内角满足关系：，且最大边长与最小边长的比值为，则；4．在△ABC中，，则；5．在△ABC中，若，则；6．在△ABC中，若，则此三角形有解7．在△ABC中，，则的余弦值为；8．边长分别为的三角形的最大角与最小角的和是；9．在△ABC中，若，那么△ABC的外接圆直径为；10．在等差数列中，若，则11．在等差数列中，若，则12．已知等差数列共有20项，所有奇数项的和为132，所有偶数项的和为112，则公差；13．在等差数列中，前项的和为，已知，则14．已知和都是等差数列，则前项的和为，且，则。二、解答题（14+14+14+16+16+16）15．①已知在△ABC中，，求和；②在△ABC中，已知，求和的值。16．已知数列是等差数列，且，求通项公式；17．已知，求的值；18．设数列的通项公式为，求19．设为等差数列，为其前项的和，已知，为数列的前项和，求；20．已知，在递增的等差数列中，①求的值；②求通项；③求的值。大丰市第二中学高二年级数学周练答题纸一、填空题1．____________________________2．____________________________3．____________________________4．____________________________5．____________________________6．____________________________7．____________________________8．____________________________9．____________________________10．____________________________11．___________________________12．____________________________13．___________________________14．____________________________二、解答题15．（14分）_______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________班级：__________姓名：__________学号：_____________________________________________________________________________________________16．（14分）__________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________17．（14分）_______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________18．（16分）_____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________19．（16分）__________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________20．（16分）_______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________参考答案：⒈⒉⒊⒋12⒌⒍一⒎⒏⒐⒑0⒒117⒓-2⒔-110⒕⒖①②⒗⒘⒙153⒚⒛①②③
