2sinX=sin(90-X)
2sinX=sin(90-X) \u6c42X2sinx=sin(90-x)
2sinx=sin90cosx-cos90sinx
2sinx=cosx
\u5f53cosx=0\u65f6\uff0c\u4e24\u8fb9\u4e0d\u76f8\u7b49\uff0c\u56e0\u6b64cosx\u22600
\u4e24\u8fb9\u540c\u65f6\u9664\u4ee5cosx
2tanx=1
tanx=1/2
x=arctan1/2+k\u03c0
2sinx=sin60cosx-cos660sinx
5sinx-cosx*\u221a3=0
\u221a(25+3)sin(x-y)=0
\u5176\u4e2dtany=\u221a3/5
x-y=k\u03c0
\u6240\u4ee5x=k\u03c0+arctan(\u221a3/5)
2sinX=cosx
tanx=1/2
x=kπ+arctan1/2
x=kπ+arctan1/2
绛旓細鍑忓彿鎴愮珛锛屽洜涓簊inx鍑芥暟鍏充簬X=90搴﹁酱瀵圭О锛屼絾鏄敼鎴愬姞鍙峰氨涓嶆垚绔嬩簡銆傚簲褰撴槸sin x = sin 锛180 - x锛锛宻in x = -sin 锛180 - x锛
绛旓細sin锛90-x锛=cosx,cos锛90+x锛=-sinx,鎵浠,cosx-sinx=1/3 鍙,cosx+sinx=1/2 涓ゅ紡鐩稿姞,寰 2cosx=5/6 鎵浠,cosx=5/12
绛旓細绠鍗曞垎鏋愪竴涓嬶紝绛旀濡傚浘鎵绀
绛旓細fx=sinx+1*cosx-0*sinx =sinx+cosx =鏍瑰彿2*sin(x+蟺/4)鐢-蟺/2+2k蟺<x+蟺/4<蟺/2+2k蟺寰 -3蟺/4+2k蟺<x<蟺/4+2k蟺 浣犳妸閭ｄ釜鍏充簬x鐨勪笉绛夊紡鍖栨垚鍖洪棿褰㈠紡鍗冲彲 璇烽噰绾
绛旓細sin(90掳-x)=cosx=²锛³cos48掳47藠=2/3 x=48掳47藠.
绛旓細鍥犱负:AD鏄腑绾 鎵浠:BC=BD+CD 鍥犱负:BC=2AB 鎵浠:AB=BD 鍙堝洜涓:鈭燘=2鈭燙 鎵浠:鈭燗=90搴 鈭燘=60搴 鈭燙=30搴 鍥犱负:AD鏄腑绾 鎵浠:鈭燗DB=2鈭燙 鎵浠:鈭燗DB=60搴 鎵浠:鈭燘AD=60搴 鎵浠モ柍ABD鏄瓑杈逛笁瑙掑舰
绛旓細鍏紡浜 璁疚变负浠绘剰瑙掞紝蟺+伪鐨勪笁瑙掑嚱鏁板间笌伪鐨勪笁瑙掑嚱鏁板间箣闂寸殑鍏崇郴锛氬浜x杞磋礋鍗婅酱涓鸿捣鐐硅酱鑰岃█ 寮у害鍒朵笅鐨勮鐨勮〃绀猴細sin锛蟺+伪锛=锛峴in伪 cos锛埾+伪锛=锛峜os伪 tan锛埾+伪锛=tan伪 cot锛埾+伪锛=cot伪 sec锛埾+伪锛=锛峴ec伪 csc锛埾+伪锛=锛峜sc伪 瑙掑害鍒朵笅鐨勮鐨勮〃绀猴細sin锛...
绛旓細褰搙=45搴︽椂锛宑osx=sinx 銆傚綋0<=x<45搴︽椂锛岃鍥俱
绛旓細80-x)/sinx ⇔2sin50+1=sin(80-x)/sinx ⇔2sin50sinx+sinx=sin(80-x)⇔2sin50sinx=sin(80-x)-sinx ⇔2sin50sinx=2cos40sin(40-x)⇔sinx=sin(40-x)⇔sinx-sin(40-x)=0 ⇔2cos20sin(x-20)=0 鑻0<x<90锛屽垯锛歺-20=0 x=20 ...
绛旓細鏍规嵁涓夎鍑芥暟鐨勮瀵煎叕寮忥紙蹇呬慨4锛,鎶婇偅鍑犱釜鍏紡璁扮啛灏变細鍋氳繖绫婚鐩簡.sin(90搴+x)+cos(270搴-x)-2sin(娲+x)-cos(90搴-x)=cosx-sinx+2sinx-sinx =cosx
