文档介绍：高三文科数学参考答案及评分标准...................... 2016. II550ABADA CAADB525}- 12. -3 13. 14. 10 5 , ?675/316?:( I )f(x) = ? cosow: ~j3cos2(ox + —.1 ? i 1 + cosliox) . J3= —sinlcjx 一—a------+ —1 . o o=—sinzo;^ ——coszaix22= sin(2似-矛),..................................................................................3分设:T为/ ( * )的最小正周期,由/ U )图象上相邻最高点与最低点的距离为v V + 4 ’得??? ( y ) 2 + [2/(*)_]2 =tt2 +4,因为/ U )咖=1,所以(| ) 2 +4 =tt2 +4,整理得 f =2tt,........................................................................................... 5 分又因为所以o>=+...................................................... 6分( II )由(I )可知/(*) =sin(* -y) ,:.f(x + <p) = sin(* +^p -y ),y =/(x +<p)是奇函数,贝!) sin(?p-y) * 0 , X 0 <^p <y,... <p=f,.............................................................................." 8 分??? g(x)= c o s ( 2 jc -(p) =cos(2名一丁),令 2/c7T容2太—号■务2A:7T + 77,( A e Z) ,则 Zc7T + 子彡jc<A:7T + 夸,A e Z ........................................................ 10 分O jr\单调递减区间是0甘+ '|1,& +子],“ 2,又*e [0,27r]当A=0时,递减区间为;7 ^当A = 1时,递减区间为[fTT,jTT].函数客U )在[0,27T]上的单调递减区间是,[ ￥ ,￥ ] ? . . . . . . . . . . . . . . .12分高三文科数学答案第1贞(共4页)17?解:.(I )???向量m与向量it共线,???(a-b) ? sin(v4 + C) = (a -c) ( sia4 + sinC) , 由正弦定理可得:(a -b)b = (a -c) (a -f-c),??? c2 = a2 + b2 -ab .cosC2ab7