绍兴市稽山中学2010学年第二学期高一数学《三角恒等变换》单元测试题一、选择题(每小题3分,共30分)1.的值为A.1B.C.D.2.若,在第二象限,则的值为A.5B.-5C.D.3.已知(,0)2x,4cos5x,则x2tan()A.247B.247C.724D.7244.sin163sin223sin253sin313()A.12B.12C.32D.325.求值000cos20cos351sin20()A.1B.2C.2D.36.在△ABC中,coscossinsinABAB,则△ABC为()A.锐角三角形B.直角三角形C.钝角三角形D.无法判定7.已知3sin(),45x则sin2x的值为()A.1925B.1625C.1425D.7258.设,则等于A.-B.-C.-9.函数))(6cos()3sin(2Rxxxy的最小值等于()A.3B.2C.1D.5110.函数22sincos()336xxy的图象中相邻两对称轴的距离是()A.B.C.D.二、填空题(每小题4分,共24分)1.若,且,则2.若的取值范围是3.已知的值等于4.=____________________5.已知2cos23,则44sincos的值为6.已知sincos13,sincos12,则sin()=__________。三、解答题(共46分)1..(本小题10分)已知,求的值.2.(本小题12分)设求的值3.(本小题12分)已知△ABC的内角B满足2cos28cos50,BB,若BCa�,CAb�且,ab满足:9ab,3,5ab,为,ab的夹角.求sin()B。4.(本小题12分)已知函数23()sincos3cos(0)2fxaxxaxaba2(1)写出函数的单调递减区间;(2)设]20[,x,()fx的最小值是2,最大值是3,求实数,ab的值.参考答案一、选择题1.D2.A3.D4.B5.C6.C7.D8.D9.C10.C二、填空题:1.2.3.4.5.18116..5972三、解答题1.2.3.解:222(2cos1)8cos50,4cos8cos50BBBB得13cos,sin22BB,34cos,sin,55abab433sin()sincoscossin10BBB4.解:133()sin2(1cos2)222afxaxxab3sin2cos2sin(2)223aaxxbaxb(1)3511222,2321212kxkkxk511[,],1212kkkZ为所求3(2)230,2,sin(2)1233323xxxminmax3()2,()3,2fxabfxab3222233aabbab4