2.解:
cosx?sinx1?tanx1?2????3
cosx?sinx1?tanx1?2sin(1800?x)1cosx3.解:原式? ??00tan(?x)tan(90?x)tan(90?x)sin(?x) ?sinx1?tanx?taxn?(?)?tanxtaxnsx in2m2?1, 4.解:由sinx?cosx?m,得1?2sinxcosx?m,即sinxcosx?2m2?13m?m3)?(1)sinx?cosx?(sinx?cosx)(1?sinxcosx)?m(1?2233
m2?12?m4?2m2?1)?(2)sinx?cosx?1?2sinxcosx?1?2( 224422数学4(必修)第一章 三角函数(上) [综合训练B组]
一、选择题 1.B tan600?0a,a??4tan6000??4tan600??43 ?42.C 当x是第一象限角时,y?3;当x是第二象限角时,y??1;
当x是第三象限角时,y??1;当x是第四象限角时,y??1 3.A 2k???2???2k???,(k?Z),4k????2??4k??2?,(k?Z),
k???4??2?k???2,(k?Z),2?在第三、或四象限,sin2??0,
cos2?可正可负;
2??在第一、或三象限,cos可正可负
22sin?m ??2cos?1?m4.B cos???1?m,tan??5.D
sin?1?cos2?sin????, 2cos?cos?cos?1?sin?sin?当?是第二象限角时,
sin?sin????tan??tan??0; cos?cos?sin?sin???tan??tan??0 cos?cos?当?是第四象限角时,
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6.B
??4?13?1?3 ,cos??sin?????3222二、填空题
1.二,?23 cos???3?,则0?是第二、或三象限角,而Py?2?0 2123,t?an???x?,?2x3 32 得?是第二象限角,则sin??2.????(2k?1)?
2?2?3.一、二 0?7.41??2,?1是第一象限角; 得
?20??9.9?9?4??得,?2是第二象限角
4.?202 ?20002??5?3060??(02 02)5.0 tan00?三、解答题
1.解:?90????90,?45?? ???0000,co0s?900,s0i?n18000,?cos2700? 0,sin3600?2?450,?900???900,
?2???(??2),?1350????2?1350
1?1411?,f()?f()?1??
33233214 ?f()?f()?0
33221221sinx?cos2xtanx?21434?7 3.解:(1)sin2x?cos2x?3?34sin2x?cos2xtan2x?1122.解:?f()?cos2sin2x?sinxcosx?cos2x(2)2sinx?sinxcosx?cosx? 22sinx?cosx222ta2nx?taxn?17? ?tanx?154.证明:右边?(1?sin??cos?)?2?2sin??2cos??2sin?cos?
2?2(1?si?n?c?o?s?sin?co
?2(1?si?n?)(1?cos)?2(1?sin?)(1?cos?)?(1?sin??cos?)2
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数学4(必修)第一章 三角函数(上) [提高训练C组]
一、选择题
1.D sin600?sin240?sin(180?60)??sin60??000003 2x21?a(a?x)cosxx???1?(?1)?(?1)?1 2.A cosx?0,1?a?0,x?a?0,x?acosxax?13.B log3sin??0,34.A 作出图形得
log3sin??3?log3sin??3log31sin??1 sin?111?sin0.5,r?,l???r? rsin0.5sin0.55.D 画出单位圆中的三角函数线
6.A (cos??cos?1?)2?(cos??cos?1?)2?4?8,cos??cos?1??22 二、填空题
771255r)?,13?,c?o?s??,?tan??,s in 在角?的终边上取点P(?12,5131312133??k1??,k(1?Z)k,?22????2k?2,2(Z ),2.一、或三 2k1??????22??k?22?????????(k1?k2?)? (k1?k2)422h?tan300h,?10 33.17.3 301.?2sin??si?n??4.二 tancos?0,c?o?s0?,s?i n05.[?2,0]?[??2???,2] A??x|k???x??k??,?k?Z?...??[333???ba2?b2aa2?b2b,tan???
aa2?b2ba2?b2a?,0]?3[??, ]...三、解答题
1.解:P(a,?b),sin??,cos??in? Q(b,a),s?,?co?s?,t?an
absin?tan?1b2a2?b2 ?????1?2??0。
cos?tan?cos?sin?aa22. 解:设扇形的半径为r,则
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S?1(20?2r)r??r2?10r 2l?2 r当r?5时,S取最大值,此时l?10,??1?sin6??cos6?1?(sin2??cos2?)(sin4??sin2?cos2??cos4?)3.解: ?44221?sin??cos?1?(1?2sin?cos?)1?(1?3sin2?cos2?)3 ??
1?(1?2sin2?cos2?)24.证明:由sin??asin?,tan??btan?,得
sin?asin??,即acos??bcos? tan?btan?2而asin??sin?,得a?bcos??sin?,即a2?b2cos2??1?cos2?,
222a2?1a2?1,而?为锐角,?cos??得cos??2 2b?1b?12数学4(必修)第一章 三角函数(下) [基础训练A组]
一、选择题 1.C 当???22?1?1??1?2.C y?sin(x?)?y?sin(x?)?y?sin[(x?)?]?y?sin(x?)
32323326时,y?sin(2x??)?cos2x,而y?cos2x是偶函数
5???????sin??cos??0???5??44?????(,)?(?,) 3.B ?424?tan??0?0????,或????5???244.D tan??1,cos??sin??1,tan??sin??cos? 5.D T?2??5? 256.C 由y?sinx的图象知,它是非周期函数 二、填空题
x1.① 0 此时f(x)?cos为偶函数
2.3 y(2?coxs?)?22y?22y?2xcosx,?cos???1?y?1y?11?y?1, 33 29
3.2,或3 T?4.?x|x?2k??5.
?k,1???2,?k??而,k?N??kk2?或2, 3???3,或2k????,k?Z? 3?,??0x?3??0x? x?[0,],?433??3? ,3?f(x)max?2sin三、解答题
??3?2,sin??3?2???3,?,?? 23441.解:将函数y?sinx,x??0,2??的图象关于x轴对称,得函数y??sinx,x??0,2??
的图象,再将函数y??sinx,x??0,2??的图象向上平移一个单位即可。
2.解:(1)sin1100?sin700,sin1500?sin300,而sin700?sin300,?sin1100?sin1500 (2)tan2200?tan400,tan2000?tan200,而tan400?tan200,?tan2200?tan2000
1111?1?0,log2?1,?2,0?sinx? sinxsinxsinx2?5???,?x?2k???,k? Z 2k??x?2k或2k??66?5?k?,k2???]k[?2?k?,2k?),Z(为所求。) (2663.解:(1)log2,是f(t)?sint的递增区间 (2)当0?x??时,?1?cosx?1,而[?11]x??时,1 当cosf(x)n(?1)?min?si?x?时,1 当cos。 f(x)1max?sin4.解:令sinx?t,t?[?1,1],y?1?sinx?2psinx?q
2;si n1y??(sinx?p)2?p2?q?1??(t?p)2?p2?q?1 y??(t?p)2?p2?q?1对称轴为t?p
当p??1时,[?1,1]是函数y的递减区间,ymax?y|t??1??2p?q?9
315ymin?y|t?1?2p?q?6,得p??,q?,与p??1矛盾;
42当p?1时,[?1,1]是函数y的递增区间,ymax?y|t?1?2p?q?9
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