sinx^2+cosx^2等于什么？
（sinx）＾2（cosx）＾2
＝（1/4）（2sinxcosx)^2
=(1/4)(sin2x)^2
=(1/4)*(1/2)(1-cos4x)
=(1/8)(1-cos4x)
sinx的最值和零点
①最大值：当x=2kπ+(π/2) ，k∈Z时，y(max)=1
②最小值：当x=2kπ+(3π/2)，k∈Z时，y(min)=-1
零值点： (kπ,0) ，k∈Z
绛旓細锛坰inx锛塣2锛坈osx锛塣2=锛1/4锛锛2sinxcosx)^2 =(1/4)(sin2x)^2=(1/4)*(1/2)(1-cos4x)=(1/8)(1-cos4x)sin²xcos²x =(1/4)[2sinxcosx]²=(1/4)sin²2x =(1/8)[2sin²x]=(1/8)[1锛峜os4x]=(1/8)锛(1/8)cos4x 涓夎鍑芥暟 涓夎鍑芥暟...
绛旓細sinx^2cosx^2=[(sin2x)/2]^2=[(sin2x)^2]/4=(1-cos4x)/8.涓嶅畾绉垎锛坰inx^2cosx^2锛=(1/8)[x-(sin4x)/4]+C=x/8-(sin4x)/32+C
绛旓細瑙ｇ瓟杩囩▼濡備笅锛氶涓sinx^2脳cos^2绛変簬锛坰inxcosx锛塣2 鍙堝洜涓簊in2x锛2sinxcosx锛屽垯sinxcosx锛1/2脳sin2x锛屽垯sinx^2脳cos^2锛濓紙1/2脳sin2x锛塣2锛1/4脳sin^2锛2x锛夛紝鍙堝洜涓1-2sin^2锛2x锛夛紳cos4x锛屽垯sin^2锛2x锛夛紳1/2脳锛1-cos4x锛夈傛墍浠ラ鐩氨鍙樻垚瀵1/8脳锛1-cos4x锛夋眰涓嶅畾绉垎銆
绛旓細sinx^2cosx^2=[(sin2x)/2]^2=[(sin2x)^2]/4=(1-cos4x)/8.涓嶅畾绉垎锛坰inx^2cosx^2锛=(1/8)[x-(sin4x)/4]+C=x/8-(sin4x)/32+C
绛旓細2sinxcosx=sin2x sinx^2cosx^2=sin2x/2 * sin2x/2=锛坰in2x)^2/4
绛旓細鍥犱负sin^4=sin^2sin^2锛岀劧鍚庢妸sin^2鎻愬彇鍑烘潵寰梥in^2(1-sin^2)=sin^2cos^2锛屼负浜嗘弿杩版柟渚匡紝鎴戠渷鐣ヤ簡x.
绛旓細cosx^2绛変簬1-(sinx)^2銆俿ecx=1/cosx锛宻ec²x=1+tan²x锛宻ecxcosx=1锛宼anx=sinxsecx銆傛鍓诧紙sec锛夋槸涓夎鍑芥暟鐨勪竴绉嶃傚畠鐨勫畾涔夊煙涓嶆槸鏁翠釜瀹炴暟闆嗭紝鍊煎煙鏄粷瀵瑰煎ぇ浜庣瓑浜庝竴鐨勫疄鏁般傚畠鏄懆鏈熷嚱鏁帮紝鍏舵渶灏忔鍛ㄦ湡涓2蟺銆2鍊嶈鍙樻崲鍏崇郴 浜屽嶈鍏紡閫氳繃瑙捨辩殑涓夎鍑芥暟鍊肩殑涓浜涘彉鎹㈠叧绯绘潵琛ㄧず...
绛旓細锛坰inx锛锛2锛坈osx锛夛季2 锛濓紙1/4锛夛紙2sinxcosx)^2 =(1/4)(sin2x)^2 =(1/4)*(1/2)(1-cos4x)=(1/8)(1-cos4x)sinx鐨勬渶鍊煎拰闆剁偣 鈶犳渶澶у硷細褰搙=2k蟺+(蟺/2) 锛宬鈭圸鏃讹紝y(max)=1 鈶℃渶灏忓硷細褰搙=2k蟺+(3蟺/2)锛宬鈭圸鏃讹紝y(min)=-1 闆跺肩偣锛 (k蟺,0) 锛宬鈭圸...
绛旓細cosx^2鐨勫叕寮忔槸锛歝osx^2=-sinx^2锛2x锛=-2xsinx^2銆備笁瑙掑嚱鏁版槸鏁板涓睘浜庡垵绛夊嚱鏁颁腑鐨勮秴瓒婂嚱鏁扮殑鍑芥暟銆傚畠浠殑鏈川鏄换浣曡鐨勯泦鍚堜笌涓涓瘮鍊肩殑闆嗗悎鐨勫彉閲忎箣闂寸殑鏄犲皠銆傞氬父鐨勪笁瑙掑嚱鏁版槸鍦ㄥ钩闈㈢洿瑙掑潗鏍囩郴涓畾涔夌殑銆傚叾瀹氫箟鍩熶负鏁翠釜瀹炴暟鍩熴傚彟涓绉嶅畾涔夋槸鍦ㄧ洿瑙掍笁瑙掑舰涓紝浣嗗苟涓嶅畬鍏ㄣ備笁瑙掑嚱鏁版帹瀵兼柟娉曪細1...
绛旓細鏍规嵁鍋跺嚱鏁扮殑瀹氫箟锛歠锛坸锛=f锛-x锛塩os锛-x锛塣2=cos(x)^2 鎵浠cosx^2涓哄伓鍑芥暟 锛坰in锛-x锛夛級^2=(-sin(x))^2=(sin(x))^2 鎵浠ワ紙sin锛坸锛夛級^2涔熸槸鍋跺嚱鏁
