高考数学复习高考专题突破二高考中的三角函数与平面向量问题市赛课公开课一等奖省名师优质课获奖PPT课件.pptx

高考专题突破二 高考中三角函数与平面向量问题,1/57,考点自测,课时训练,题型分类深度剖析,内容索引,2/57,考点自测,3/57,答案,解析,4/57,5/57,2.,在,ABC,中，,AC,cos,A,3,BC,cos,B,，且,cos,C,则,A,等于,A.30 B.45,C.60 D.120,答案,解析,6/57,由题意及正弦定理得,sin,B,cos,A,3sin,A,cos,B,，,tan,B,3tan,A,，,0,A,90,，,0,c,，所以,a,3,，,c,2.,31/57,(2)cos(,B,C,),值,.,解答,因为,a,b,c,，所以,C,为锐角，,32/57,课时训练,33/57,解答,1,2,3,4,5,6,34/57,解答,1,2,3,4,5,6,35/57,1,2,3,4,5,6,36/57,2.(,山东,),设,f,(,x,),sin(,x,)sin,x,(sin,x,cos,x,),2,.,(1),求,f,(,x,),单调递增区间；,解答,1,2,3,4,5,6,37/57,1,2,3,4,5,6,38/57,解答,1,2,3,4,5,6,39/57,把,y,f,(,x,),图象上全部点横坐标伸长到原来,2,倍,(,纵坐标不变,).,1,2,3,4,5,6,40/57,解答,设在,ABC,中，角,A,，,B,，,C,对边分别为,a,，,b,，,c,，,可得,tan,1,，,1,2,3,4,5,6,41/57,1,2,3,4,5,6,解答,42/57,函数,f,(,),值域是,2,，,3,.,1,2,3,4,5,6,43/57,解答,(1),求,及图中,x,0,值；,1,2,3,4,5,6,44/57,因为,f,(,x,),最小正周期等于,2,，,所以由题图可知,1,x,0,2,，,1,2,3,4,5,6,45/57,解答,1,2,3,4,5,6,46/57,1,2,3,4,5,6,47/57,1,2,3,4,5,6,48/57,解答,1,2,3,4,5,6,49/57,即,sin,A,cos,B,4cos,A,sin,B,，,1,2,3,4,5,6,50/57,(2),求,tan(,A,B,),最大值,解答,1,2,3,4,5,6,51/57,由,(1),得,tan,A,4tan,B,0,，,1,2,3,4,5,6,52/57,解答,1,2,3,4,5,6,53/57,因为,x,R,，,1,2,3,4,5,6,54/57,解答,1,2,3,4,5,6,55/57,1,2,3,4,5,6,56/57,1,2,3,4,5,6,57/57,