【正文】 two years of time to learn to speak, but to spend a few years time to shut up. That is a kind of ability, that is a kind of wisdom. 16, life is not perfect, sometimes, growth is not a cry, not an eyeful of tears, there is no trace of emotion, there is no gleam of hope, no desire, no action, no static, there is only one kind of downward sinking feeling, sink A murky? 6? 7? 6? 7 sink? 6? 7? 6? 7 toward the bottom of the sink. 17, in some way, do not go, you will not know the other side scenery is beautiful. To you is not good, you do not mind too much, no one has an obligation to you。t envy him A sum of, don39。am, like a movie, learn to appreciate, learn to be grateful, learn tolerance, and goodness, helping others. Instead of accusing the society, as into one。t envy who. Like a person is a kind of feeling, not like a person is true. The truth is easy to explain, I feel Is unspeakable. The best travel life is that you in a strange place found a long lost touched. 11, happy life not in the bustling in, and in the peace of mind。s mouth, because words will reduce its importance。 you pain, no one can understand. Then you only tears to smile. 8, each people have youth, Each youth are a story, the life of the world never gets easier, I want what, wish the world all know, as has been the same。 loss of sink, Eritrea pany. When you are in adversity, may wish to change a point of view to think everything over to the good Think, because good mentality decided the fate of the! 7, people are tired, rest。 and when we are in a negative state of mind, you will find many depressed things。m afraid he turned to it as a joke to tell don39。t be narrowminded. Poke to care, is a kind of openminded, a free and easy. 5, I am not afraid of others behind me a knife, I afraid to look back and see stab me, is my intention to treat people。t get into a blind alley, don39。 not unrewarding perfunctorily, but calm attitude of life of unrestrained selfconfidence. Plain living, there is no noise noisy, no earthly troubles, more did not fill in the discontent of desire, some just a calm, a calm. 3, memory of heart will not good things to erase the, life is a When no movie, pain is a beginning, the struggle is a kind of process, death is a kind of ending. Give up this giving up is the helpless, do not give up the abandoned, do not give up this giving up is ignorance, do not give up should not give up is persistent. 4, a thing figured is heaven, think impassability is hell. Since the living, to live better. Sometimes we because of too narrowminded, too care around the chores and penny wise and pound foolish, not worth the candle. Some things to attract trouble and worry, pletely depends on how we look at and deal with it. Don39。 not to have conquered, but to have fought well. 2, the plain is the background of life. Live a plain life, give up on themselves is not a coward, but the wise answers。 to implement , do not want to, dare not, not with disciplinary ruler to supervision。 若零點(diǎn)在區(qū)間的端點(diǎn) ,則僅在區(qū)間左或右端點(diǎn)處得一個(gè)區(qū)間含 3 個(gè)零點(diǎn) ,其它區(qū)間仍是 2 個(gè)零點(diǎn) 。 (II)若 ( , )2???? ,且 22f ? ?（ ） ,求 ? 的值 . 【答案】 解 :(I)因?yàn)?2 1( 2 c os 1 ) sin 2 c os 42f x x x x? ? ?（ ）= 1c os 2 si n 2 c os 42x x x? = 1 (si n 4 cos 4 )2 xx?= 2 sin(4 )24x ??,所以 ()fx的最小正周期為2?,最大值為 22. (II)因?yàn)?22f ? ?（ ）,所以 sin(4 ) 14?? ??. 因?yàn)?( , )2????, 所以 9 174 ( , )4 4 4? ? ?? ??,所以 5442?????,故 916???. 41． （ 2020 年上海高考數(shù)學(xué)試題（文科）） 本題共有 2個(gè)小題 .第 1小題滿分 6分 ,第 2小題滿分 8分 . 已知函數(shù) ( ) 2 sin( )f x x?? ,其中常數(shù) 0?? . (1)令 1?? ,判斷函數(shù) ( ) ( ) ( )2F x f x f x ?? ? ?的奇偶性并說(shuō)明理由 。 (Ⅱ) 不畫(huà)圖 ,說(shuō) 明函數(shù)()y f x?的圖像可由sinyx?的圖象經(jīng)過(guò)怎樣的變化得到 . 【答案】 解 :(1)3sincos3cossinsin)( ?? xxxxf ??? xxxx cos2 3sin23cos2 3sin21sin ????? )6sin(3)6sin()2 3()23( 22 ?? ??? xx 當(dāng)1)6sin( ????x時(shí) ,3)( min ??xf,此時(shí))(,234,2236 Zkkxkx ??????? ????? 所以 ,)(xf的最小值為3?,此時(shí) x 的集合},234|{ Zkkxx ?? ??. (2)xy sin?橫坐標(biāo)不變 ,縱坐標(biāo)變?yōu)樵瓉?lái)的 倍 ,得xy sin3?。(2) 若 C=23? ,求 ab 的值 . 【答案】 解 :(1)由已知得 sinAsinB+sinBsinC+12sin2B= sinAsinB+sinBsinC=2sin2B 因?yàn)?sinB 不為 0,所以 sinA+sinC=2sinB 再由正弦定理得 a+c=2b,所以 a,b,c成等差數(shù)列 (2)由余弦定理知 2 2 2 2 c o sc a b ac C? ? ? 得 2 2 2 2( 2 ) 2 c o s3b a a b a c ?? ? ? ?化簡(jiǎn)得 35ab? 38． （ 2020 年 高 考湖 北卷 （文）） 在 △ ABC 中 ,角 A , B , C 對(duì)應(yīng)的邊分別是 a , b , c . 已知c o s 2 3 c o s ( ) 1A B C? ? ?. (Ⅰ) 求角 A 的大小 。 (Ⅱ) 設(shè) 3a? ,S 為 △ ABC 的面積 ,求 3cos cosS B C? 的最大值 ,并指出此時(shí) B 的值 . 【答案】 36． （ 2020 年高考四川卷（文） ） 在 ABC? 中 ,角 ,ABC 的對(duì)邊分別為 ,abc,且 3c os ( ) c os sin ( ) sin ( ) 5A B B A B A c? ? ? ? ? ?. (Ⅰ) 求 sinA 的值 。fx?ab . (Ⅰ) 求 f (x)的最小正周期 . (Ⅱ ) 求 f (x) 在 0,2???????上的最大值和最小值 . 【答案】 (Ⅰ) () 33． （ 2020 年高考福建卷（文）） 如圖 ,在等腰直角三角形OPQ?中 ,90OPQ??,22OP?,點(diǎn) M在線段PQ上 . (1)若3OM?,求 PM的長(zhǎng) 。 (Ⅱ) 若 a=6,b+c=8,求 △ABC 的面積 . 【答案】 解 :(Ⅰ) 由已知得到 : 2 s in s in 3 s inA B B?,且 3(0 , ) s i n 0 s i n22B B A?? ? ? ? ?,且 (0 , )23AA??? ? ?。 (Ⅱ ) 求sin 2 3B ????????的值 . 【答案】 30． （ 2020 年高考廣東卷（文）） 已知函數(shù) ( ) 2 c o s ,12f x x x R???? ? ?????. (1) 求3f ???????的值 。 26． （ 2020 年高考江西卷（文）） 設(shè) f(x)= sin3x+cos3x,若對(duì)任意實(shí)數(shù) x 都有 |f(x)|≤a, 則實(shí)數(shù) a 的取值范圍是 【答案】 2a? 三、解答題 27． （ 2020 年高考大綱卷（文）） 設(shè) ABC? 的內(nèi)角 ,ABC 的對(duì)邊分別為 ,abc, ( ) ( )a b c a b c ac? ? ? ? ?. (I)求 B (II)若 31si n si n4AC ??,求 C . 【答案】 (Ⅰ) 因?yàn)?( ) ( )a b c a b c ac? ? ? ? ?, 所以 2 2 2a c b ac? ? ? ?. 由余弦定理得 , 2 2 2 1c o s 22a c bB ac??? ? ?, 因此 , 0120B? . (Ⅱ) 由 (Ⅰ) 知 060AC?? ,所以 c o s( ) c o s c o s sin sinA C A C A C? ? ? c o s c o s s i n s i n 2 s i n s i nA C A C A C? ? ? c o s( ) 2 sin sinA C A C? ? ? 1 3 1224?? ? ? 32? , 故 030AC?? 或 030AC? ?? , 因此 , 015C? 或 045C? . 28． （ 2020 年高考湖南（文）） 已知函數(shù) f(x)= (1) 求2()3f ?的值 。 2020 年全國(guó)各地高考文科數(shù)學(xué)試題分類(lèi)匯編：三角函數(shù) 一、選擇題 1 ． （ 2020 年高考大綱卷（文）） 已知 a 是第二象限角 , 5si n , cos13aa??則（ ） A． 1213? B． 513? C． 5