cos2π的导数
结果是0啊绛旓細鈭玔0, 2蟺] cos(2x) * P₀(x) dx = 0 鈭玔0, 2蟺] cos(2x) * P₁(x) dx = 0 鈭玔0, 2蟺] cos(2x) * P₂(x) dx = 0 鈭玔0, 2蟺] cos(2x) * P₃(x) dx = 0 鐒跺悗锛屽埄鐢ㄦ浜ゆф潯浠舵潵瑙ｆ柟绋嬬粍锛屾眰瑙ｅ嚭绯绘暟 c₀銆乧₁銆乧&#...
绛旓細sin(蟺 y^2) 杩欐槸澶嶅悎鍑芥暟姹傚 绗竴姝ュ厛瑕佸sin(蟺 y^2)姹傚锛屽緱鍒 cos(蟺 y^2)*锛埾 y^2锛'绗浜姝ュ氨瑕佸 蟺 y^2 姹傚锛屽洜涓簓 涓嶆槸甯告暟锛岃屾槸x鐨勫嚱鏁帮紝鎵浠ヤ笉鑳芥妸瀹冪畝鍗曠殑褰撳仛涓涓父鏁板垎鍑哄幓锛岃屽簲璇ユ帴鐫瀵箉姹傚锛屽緱鍒 锛埾 y^2锛'=蟺(y^2)'=蟺(2y*y')...
绛旓細cos(x+dx)=cosx*cosdx-sinx*sindx 鎵浠(cos(x+dx)-cosx)=cosx*(cosdx-1)-sinx*sindx 褰揹x瓒嬭繎浜0鏃讹紝cosdx瓒嬭繎浜1锛屾墍浠ュ墠鍗婇儴鍒嗕负0锛屽悗鍗婇儴鍒嗕负 -sinx*sindx/dx=-sinx*(sindx/dx)锛屽綋dx瓒嬭繎浜0鏃讹紝sindx/dx瓒嬭繎浜1锛屾墍浠ュ悗鍗婇儴鍒嗙瓑浜-sinx 缁间笂鎵杩帮紝瀵兼暟=2cosx*(-sinx)=...
绛旓細鍙︿竴涓弻绾界嚎鐨勬柟绋嬫槸锛毾乛2=a^2*sin2胃 鏋佸潗鏍囨柟绋嬩笅锛歺=蟻cos胃,y=蟻sin胃 瀵兼暟鏂圭▼ 蟻^2=a^2*cos2胃鐨勫鏁鏂圭▼锛毾=-1*sin(2胃)*cos(2胃)^(-0.5)蟻^2=a^2*sin2胃鐨勫鏁版柟绋嬶細蟻=sin(2胃)^(-0.5)*cos(2胃)锛屽弻绾界嚎鍙氳繃绛夎酱鍙屾洸绾跨粡杩囧弽婕斿緱鍒般
绛旓細璁颁綇鍩烘湰瀵兼暟鍏紡 (cosx)'= -sinx 鎵浠ュ彲浠ュ緱鍒癲cos²x =2cosx dcosx = -2cosxsinx dx = -sin2x dx
绛旓細cos2x鐨勫鏁帮細-2sin2x銆傝繖鏄竴涓鍚堝嚱鏁扮殑瀵兼暟锛屾湁涓ゅ眰锛屽灞傛槸cos鐨勫鏁锛屽唴灞傛槸2x鐨勫鏁帮紝鎵浠(cos2x)'=-sin2x*(2x)鐨勫鏁=-2sin2x銆傝В锛(cos2x)'=-sin2x*(2x)'=-2sin2x 瀵兼暟锛屼篃鍙鍑芥暟鍊笺傚張鍚嶅井鍟嗭紝鏄井绉垎涓殑閲嶈鍩虹姒傚康銆傚綋鍑芥暟y=f锛坸锛夌殑鑷彉閲弜鍦ㄤ竴鐐箈0涓婁骇鐢熶竴涓...
绛旓細鏂规硶濡備笅锛岃浣滃弬鑰冿細
绛旓細cos(x+dx)=cosx*cosdx-sinx*sindx 鎵浠(cos(x+dx)-cosx)=cosx*(cosdx-1)-sinx*sindx 褰揹x瓒嬭繎浜0鏃讹紝cosdx瓒嬭繎浜1锛屾墍浠ュ墠鍗婇儴鍒嗕负0锛屽悗鍗婇儴鍒嗕负 -sinx*sindx/dx=-sinx*(sindx/dx)锛屽綋dx瓒嬭繎浜0鏃讹紝sindx/dx瓒嬭繎浜1锛屾墍浠ュ悗鍗婇儴鍒嗙瓑浜-sinx 缁间笂鎵杩帮紝瀵兼暟=2cosx*(-sinx)=...
绛旓細1-cosx绛変簬1/2(sinx/2)^2銆傚師寮=cos(2x)=(cosx)^2-(sinx)^2 =2(cosx)^2-1 =1-2(sinx)^2cos(2x)=1-2(sinx)^2 =1-2(sinx/2)^2 =1/2(sinx/2)^2 sin鍜cos鐨鍏崇郴鏄細sin伪+cos伪=1锛泂inx=cos锛90-x锛夛紱tan伪=sin伪/cos伪锛泂in骞虫柟伪*cos骞虫柟伪=1銆俿in伪鏄寮︼紝cos...
绛旓細1.灏cos(2x-蟺/3)鐪嬫垚鏁翠綋鈭歝os(2x-蟺/3)鐨勫鏁鏄1/[2鈭歝os(2x-蟺/3)] 灏2x-蟺/3鐪嬫垚鏁翠綋cos(2x-蟺/3)鐨勫鏁版槸-sin(2x-蟺/3) 2x-蟺/3鐨勫鏁版槸2 鏍规嵁澶嶅悎鍑芥暟姹傚鐨勫師鐞唝'=1/[2鈭歝os(2x-蟺/3)]*[-sin(2x-蟺/3)]*2=-sin(2x-蟺/3)/鈭歝os(2x-蟺/3) 缁欎釜濂借瘎鍚 ...
