高考數(shù)學(xué)專題復(fù)習(xí)導(dǎo)練測(cè) 第五章 平面向量階段測(cè)試(七)課件 理 新人教A版.ppt
,數(shù)學(xué) A(理),45分鐘階段測(cè)試(七),第五章 平面向量,2,3,4,5,6,7,8,9,10,1,2,3,4,5,6,7,8,9,10,1,A,3,4,5,6,7,8,9,10,1,2,2.(2014四川)平面向量a(1,2),b(4,2),cmab(mR),且c與a的夾角等于c與b的夾角,則m等于( ) A.2 B.1 C.1 D.2 解析 因?yàn)閍(1,2),b(4,2), 所以cmab(m,2m)(4,2)(m4,2m2).,D,2,4,5,6,7,8,9,10,1,3,3.已知A( ,0),B(0,1),坐標(biāo)原點(diǎn)O在直線AB上的射影為點(diǎn)C,則 等于( ) 解析 由題意知|AB|2,|OC| OAC30,AOC60,,B,2,3,5,6,7,8,9,10,1,4,2,3,5,6,7,8,9,10,1,4,2,3,4,6,7,8,9,10,1,5,2,3,4,6,7,8,9,10,1,5,2,3,4,5,7,8,9,10,1,6,(4,7),2,3,4,5,6,8,9,10,1,7,2,3,4,5,6,8,9,10,1,7,2,3,4,5,6,9,10,1,7,8,2,2,3,4,5,6,7,8,10,1,9,2,3,4,5,6,7,8,10,1,9,(2)設(shè)c(0,1),若abc,求,的值. 解 因?yàn)閍b(0,1),,又0, cos cos cos(),則, sin sin()1,,2,3,4,5,6,7,8,10,1,9,10.如圖所示,A、B分別是單位圓與x軸、y 軸正半軸的交點(diǎn),點(diǎn)P在單位圓上,AOP (0),C點(diǎn)坐標(biāo)為(2,0),平行四邊 形OAQP的面積為S. (1)求 S的最大值; 解 由已知,得A(1,0),B(0,1),P(cos ,sin ). 因?yàn)樗倪呅蜲AQP是平行四邊形,,2,3,4,5,6,7,8,9,1,10,2,3,4,5,6,7,8,9,1,10,2,3,4,5,6,7,8,9,1,10,2,3,4,5,6,7,8,9,1,10,