高一数学，如何化简三角函数，急！～
\u9ad8\u4e00\u6570\u5b66\uff01\uff01\u4e09\u89d2\u51fd\u6570\u5316\u7b80\uff01\uff01\uff01\uff01\u8fd9\u4e2a\u5f97\u7528\u516c\u5f0f\u3002\u3002\u3002cos2X+1=2cos^2x-1+1=2cos^2x
tanx/2-cotx/2=sinx/(1+cosx)-sinx/(1-cosx)=-2cosx/sinx=-1/2sin2x
\u6253\u6570\u5b66\u7b26\u53f7\u90fd\u6655\u4e86\uff0c\u4f30\u8ba1\u5f97\u6709\u70b9\u9519\u8bef\u3002
\u4e0d\u8fc7\u697c\u4e3b\u8981\u638c\u63e1\u597d\u6570\u5b66\u516c\u5f0f\u5c31\u6ca1\u95ee\u9898\u4e86\u54e6\uff01
=(sin\u03b1)^2-(sin\u03b1)^2(sin\u03b2)^2+\uff08sin\u03b2\uff09^2+\uff08cos\u03b1\uff09^2\uff08cos\u03b2\uff09^2
=(sin\u03b1)^2[1-(sin\u03b2)^2]+\uff08sin\u03b2\uff09^2+\uff08cos\u03b1\uff09^2\uff08cos\u03b2\uff09^2
=(sin\u03b1)^2\uff08cos\u03b2\uff09^2+\uff08cos\u03b1\uff09^2\uff08cos\u03b2\uff09^2+\uff08sin\u03b2\uff09^2
=\uff08cos\u03b2\uff09^2[(sin\u03b1)^2+\uff08cos\u03b1\uff09^2]+\uff08sin\u03b2\uff09^2
=\uff08cos\u03b2\uff09^2+\uff08sin\u03b2\uff09^2
=1
2、2（根号3/2sin(x/2)+1/2cos(x/2)）=2sin(x/2+π/6)
3、原式=sin(360-13)cos(180-32)+sin(90-13)cos(90-32)
=(-sin13)(-cos32)+cos13sin32
=sin13cos32+cos13sin32
=sin(13+32)=sin45=根号2/2
1、原式=6√5((√3/2)sinx+(1/2)cosx)=6√5（sinx cos π/6+cosx sinπ/6）=6√5sin(x+π/6)
3、原式=2(√3/2sin(x/2)+1/2cos(x/2)）
=2(sinx cos π/6+cosx sinπ/6)
=2sin(x/2+π/6)
5、原式=sin(360°-13°)cos(180°-32°)+sin(90°-13°)cos(90°-32°)
=(-sin13°)(-cos32°)+cos13°sin32°
=sin13°cos32°+cos13°sin32°
=sin(13°+32°)=sin45°=√2/2
绛旓細1銆佸垏鍖栧鸡涓庡鸡鍖栧垏銆2銆佹湁鍒嗗紡,鍙互鑰冭檻閫氬垎銆傞氬垎鍚庢诲彲浠ュ埄鐢ㄥ拰瑙掑叕寮忔垨杈呭姪瑙掑叕寮忚繘琛屽寲绠銆3銆鍑忓皯瑙銆傚鏈20搴,70搴,閭ｄ箞鍙互鍒╃敤70搴=90搴-20搴﹁繘琛岃浆鍖栥4銆佸噺灏戜笁瑙掑嚱鏁板悕銆傚笇鏈涜兘瀵逛綘鏈夌敤銆備細鎬荤粨鐨勫涔犳墠鏄珮鏁堝涔! 鏈洖绛旂敱鎻愰棶鑰呮帹鑽 涓炬姤| 绛旀绾犻敊 | 璇勮 8 14 鑰佽檸浜屽摜 閲囩撼鐜:61% ...
绛旓細1銆佸師寮=6鈭5((鈭3/2)sinx+(1/2)cosx)=6鈭5锛坰inx cos 蟺/6+cosx sin蟺/6锛=6鈭5sin(x+蟺/6)2銆佸師寮= 鈭3((鈭3/2)cosx-(1/2)sinx)=鈭3(sin蟺/3cosx-cos 蟺/3 sinx)=鈭3sin(蟺/3-x)3銆佸師寮=2(鈭3/2sin(x/2)+1/2cos(x/2)锛=2(sinx cos 蟺/6+cosx sin...
绛旓細锛1锛夊厛鐢ㄥ畬鍏ㄥ钩鏂瑰叕寮忓睍寮锛屽啀鍒╃敤sin² 伪+cos² 伪=1鍖栫畝銆傦紙2锛鍏堢敤璇卞鍏紡鍖栫畝锛屽啀鍒╃敤鍟嗙殑鍏崇郴寰楀嚭缁撴灉銆傘愭楠ゃ戯紙1锛夊師寮=sin² 伪+2sin 伪cos 伪+cos² 伪+sin² 伪-2sin 伪cos 伪+cos² 伪 =2(sin² 伪+cos² 伪)=2 锛2锛夊師...
绛旓細1銆佸師寮=sin伪路(-cos伪)=-1/2脳2sin伪路(-cos伪)=-1/2sin2伪 2銆佸師寮=-cos伪路(-sin伪)路cos伪 =sin伪路cos²伪
绛旓細绗竴涓垎寮忓垎姣嶆牴鍙蜂腑鐨(tan伪)^2=(sin伪)^2/(cos伪)^2锛屼唬鍏ヨ绠楋紱绗簩涓牴鍙蜂腑鍒嗗瓙鍜屽垎姣嶅悓鏃朵箻锛1+sin伪锛夛紱绗笁涓牴鍙蜂腑鍒嗗瓙鍜屽垎姣嶅悓鏃朵箻锛1-sin伪锛夛紱鏈鍚庣粨鏋滃簲璇ヤ负锛1+2/|cos伪|锛
绛旓細璇佹槑锛3/sin²40掳-1/cos²40掳 =(3cos²40掳-sin40掳)/(sin²40掳cos²40掳)=(鈭3cos40掳+sin40掳)(鈭3cos40掳-sin40掳)/[(1/4)*(2sin40掳cos40掳)²]=4*[(鈭3/2)cos40掳+(1/2)sin40掳]*[(鈭3/2)cos40掳+(1/2)sin40掳]/[(1/...
绛旓細=-cot胃 sin(胃-3蟺/2)=-sin(3蟺/2 -胃)=sin(蟺/2+胃)=cos胃 [sin(胃+3蟺)]^2 =(sin胃)^2 tan(胃+蟺/2).sin(胃-3蟺/2).[sin(胃+3蟺)]^2 =(-cot胃).cos胃.(sin胃)^2 = -(cos胃)^2.(sin胃)tan(蟺+胃) = tan胃 [cos(-蟺-胃)]^3 =[cos(蟺+胃)]^3 ...
绛旓細1,锛塻in164掳sin224掳+sin254掳sin314掳 =sin164掳sin224掳+sin(164掳+90掳)sin锛224掳+90掳锛=sin164掳sin224掳+cos164掳cos224掳 =cos锛224掳-164掳锛=cos60掳=1/2 2.)sin(伪+尾)cos锛埼-尾锛-cos锛埼+伪锛塻in锛埼-纬锛=sin(伪+尾)cos锛埼-尾锛+cos锛埼+尾锛塻in锛埼-尾锛...
绛旓細鍥炵瓟锛氬師寮=[(-sina)*(cosa)*(cosa)]/[(-cosa)*(sina)] =cosa銆
绛旓細cos2X=(cosX)^2-(sinX)^2 =2*(cosX)^2-1 =1-2*(sinX)^2 f(x)=(1+cos2X)*(sinX)^2=2[1-(sinX)^2]*(sinX)^2=2*(cosX)^2*(sinX)^2=2(sin2X)^2
