高一数学题目,三角函数得到基础题,我学的不好,请有才能的人不吝与分数,帮帮忙,写下过程
\u9ad8\u4e00\u6570\u5b66\uff0c\u4e09\u89d2\u51fd\u6570\uff0c\u8bf7\u6709\u624d\u80fd\u7684\u4eba\u4e0d\u541d\u5206\u6570\u8d50\u6559\uff0c\u5199\u4e0b\u8fc7\u7a0b\uff0c\u5e2e\u52a9\u6211\u7406\u89e3\u9898\u76ee\uff0c\u6211\u5b66\u7684\u4e0d\u597dy=sin²x+sinx-1=( sinx+1/2)^2-5/4
\u56e0\u4e3a-1<=sinx<=1,\u800c\u4e140<=( sinx+1/2)^2<=(3/2)^2=9/4
\u6240\u4ee5\u51fd\u6570y=sin²x+sinx-1\u7684\u503c\u57df\u4e3a\u662f[-5/4 ,1]
\u89e3\uff1a\u4e0e--496\u5ea6\u7ec8\u8fb9\u76f8\u540c\u7684\u89d2\u662f\uff1a224\u5ea6+K*360\u5ea6\uff08K\u5c5e\u4e8e\u6574\u6570\uff09\uff0c
\u5b83\u662f\u7b2c\u4e09\u8c61\u9650\u89d2\uff0c
\u5b83\u4eec\u4e2d\u6700\u5c0f\u6b63\u89d2\u662f224\u5ea6\uff0c\u6700\u5927\u8d1f\u89d2\u662f--136\u5ea6\u3002
所以N=(-540°,540°)
所以 M∩N=(-360°,450°)
不好意思,这个没有什么过程,你可能还没有理解集合
(-2π,-2π+二分之π)∪(0,二分之π)∪(2π,2π+二分之π)
绛旓細濡傛灉鎶婂畠褰撳仛涓夎鍑芥暟鐨勮瘽 M={a|k360掳<a<k360掳+90掳} 蟺绾︾瓑浜3.14 10绾︾瓑浜3蟺 鎵浠=锛-540掳锛540掳锛夋墍浠 M鈭㎞=锛-360掳,450掳锛
绛旓細濡傛灉鍚庨潰鎺ョ殑涓嶆槸瑙掑害锛屽氨鏄唬琛ㄦ帴鐨勫姬搴︼紝涓寮у害绾︾瓑浜57瑙掑害銆傚洜姝in1=sin57搴︺備竴涓猵i锛堝渾鍛ㄧ巼锛夌瓑浜180搴︺俛/2鍦ㄧ浜屽儚闄愶紝鎵浠ina/2澶т簬0涓斿皬浜1锛屼竴寮у害鍦ㄧ涓璞¢檺锛屾墍浠an(sina/2)澶т簬0銆俢osa灏忎簬闆跺ぇ浜庤礋涓锛宻in锛坈osa锛夊皬浜庨浂锛屾墍浠ユ渶缁堢粨鏋滃皬浜0锛岃礋鏁 ...
绛旓細杩欎綅鍚屽锛屾棰樹富瑕佸浣欏鸡鍑芥暟鐨勫浘鍍忓強鎬ц川寰堢啛鎮夋墠瀹规槗姹傝В锛宖(x)鍦╗鍏锛2鍏]涓婁笉鏄鍑芥暟锛屸憼鈶⑩懁姝g‘锛屼綘鍙互澶氬瀛︿範涓夎鍑芥暟鐨勫熀纭鐭ヨ瘑锛屽笇鏈涘浣犳湁鎵甯姪锛
绛旓細涓銆侊紙1锛夆埖0鈮鈮は/2锛屸埓-蟺/6鈮2x-蟺/6鈮5蟺/6锛屸埓-1/2鈮in锛2x-蟺/6锛夆墹1锛屸埓b鈮锛坸锛夆墹3a+b銆傛湁宸茬煡锛宐=-5锛3a+b=1锛岃В寰楋細a=2锛宐=-5.锛2锛塯锛坸锛=f锛坸+蟺/2锛=4sin(2x-蟺/6)-1,鐢眊锛坸锛>1锛屸埓sin(2x-蟺/6)锛1/2.鑰-蟺/6鈮2x-蟺/6鈮5蟺/6...
绛旓細涓夛細y=sin(x+蟺/4)鐨勫鍖洪棿鏄紵2k蟺-蟺/2鈮+蟺/4鈮2k蟺+蟺/2 2k蟺-3蟺/4鈮鈮2k蟺+蟺/4 鍥涳細y=cos²x-3cosx+2鐨勬渶灏忓 y=(cosx-3/2)²-1/4 cosx=1,min(y)=0 浜旓細鑻鍑芥暟y=2sinx(kx+蟺/5)鐨勬渶灏忔鍛ㄦ湡涓2蟺/3锛屽垯姝f暟k=?(2蟺/3)k=2蟺 k=3 ...
绛旓細鐪嬮掑閮ㄥ垎灏辫 3.鐢ㄨ瀵煎叕寮 涓嶇煡閬撲綘浠浜嗘病 鍥犱负f(x)=2sin(2x+伪+pai/6)婊¤冻0<伪<pai涓哄鍑芥暟锛a+pai/6鍖呭惈鍦╬ai/6鍒7pai/6 鏍规嵁璇卞鍏紡 a+pai/6=pai 鎵浠 a=5pai/6 鍓╀笅鐨勫洖绛斿お澶氫簡鎳掑緱瑙d簡 澶氱湅涔﹀惂锛屾垜鐪嬩簡涓涓嬭繖浜涢兘鏄畝鍗曠殑鍩虹棰 ...
绛旓細sin(A+B)-sin(A-B)=2cosAsinB=3/5-1/5=2/5 鎵浠osAsinB=1/5 锛坰inAcosB锛/锛坈osAsinB锛=锛2/5锛/锛1/5锛夛紳2 鍗硉gActgB锛2 璁続B杈逛笂鐨勯珮涓篊D锛孌涓哄瀭瓒 鍒檛gActgB锛(CD/AD)*(BD/CD)=BD/AD=2 鍥犱负AB=3 鎵浠D=1,BD=2 鍥犱负ABC鏄攼瑙涓夎褰 鎵浠0掳<鈭燙<90掳 鎵浠90...
绛旓細鎴戣寰棰樼洰搴旇鏄痵in^4@+sin^2@cos^2@+cos^2@=1鍚 璇佹槑锛歴in^4@+sin^2@cos^2@+cos^2 =sin^2@sin^2@+sin^2@cos^2@+cos^2 =sin^2@锛坰in^2@+cos^2@锛+cos^2 =sin^2@+cos^2 =1
绛旓細绠鍗曘傜粨棰樻濊矾鏄笂闈㈡妸1鍖栨垚sin骞虫柟-COS骞虫柟锛屽彉鎴愬畬鍏ㄥ钩鏂瑰紡锛堟敞鎰忔牴鍙峰唴瑕佸ぇ浜庣瓑浜0锛変笅闈㈡妸鏍瑰彿鍐呭彲鍙樻垚sin10搴︼紝浣犳妸涓婁笅淇╀釜涓闄ゅ氨OK浜嗐
绛旓細楂樹竴璨屼技鏄涓夎鍑芥暟姣旇緝閲嶈锛屼竴鑸珮鑰冪殑绗竴閬撳ぇ棰樺氨鏄畠浜嗭紝10鍒嗘垨鑰12鍒嗭紝灞炰簬鍩烘湰鐨勫緱鍒棰橈紝鎵浠ユ兂鑰冮珮鍒嗚繖閬撻鏄繀椤绘嬁涓嬫潵鐨勩傚叾瀹炰笉鏄潪甯搁毦锛屽氨鏄竴浜涘熀鏈殑鍏紡锛屼粈涔堝鍙樺伓涓嶅彉锛岀鍙风湅璞¢檺..杩樻湁鍜屽樊瑙掑叕寮忥紝浜屽嶈鍏紡涔嬬被鐨勶紝鍒嗘竻sin涓巆os鐨勫尯鍒紝闇瑕佹敞鎰忕殑灏辨槸閭d簺鍏紡鏈夌殑姣旇緝瀹规槗...