²»¶¨»ý·Ösinxcosx/1+sin4x dx

2008-03-05 ¡Òsinxcosx/(1+sin^4x)dx 156 2014-12-22 Çó(sinxcosx)/(1+(sinx)^4)µÄ²»¶¨»ý·Ö 2017-04-25 Çósin x*cos x/(1+sin^4 x)µÄ²»¶¨»ý·Ö 2013-03-28 ¡Òsinx/(1+sin^4x) dxÔõô×ö°¡? 2012-04-27 1/(sinxcos^4x)µÄ²»¶¨»ý·Ö 51

(sinx)^4+(cosx)^4+sin4xµÄ×îСÕýÖÜÆÚ

£¨sinx£©^4+£¨cosx£©^4+sin4x =[(sinx)^2+(cosx)^2-2(sinxcosx)^2+sin4x =1-(sin2x)^2/2+sin4x =(1/3)cos(4x)+sin4x+3/4 cosx,sinx×îСÕýÖÜÆÚ2...

ÒÑÖªº¯Êýf(x)=sin4x+cos4x(×¢:ÒòΪÎÒ²»»á´ò4´Î·½,Æäʵ...

f(x)=(sinx)^4+(cosx)^4f(x)=[(sinx)^2+(cosx)^2]^2-2(sinx)^2(cosx)^2f(x)=1-(sin2x)/2-1

ÒÑÖªº¯Êýf(x)=cos4x+2sinxcosx - sin4x.(1)Çóf(x)µÄ×îС...

½â´ð:½âÎö:f(x)=cos4x+2sinxcosx-sin4x=(cos2x-sin2x)(cos2x+sin2x)+2sinxcosx=cos2x+sin2x=2sin(2x+¦Ð4) (1)×îСÕýÖÜÆÚT=2¦Ð2=¦Ð(2)µ±x¡Ê[0,...

½«º¯Êýfx=sin4x+cos4xÕ¹³ÉxµÄÃݼ¶Êý

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¡Ò(cosx+ sinx) dxÔõô»ý·Ö?

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ÒÑÖªsin^4x+cos^4x=1,Çósinx+cosxµÄÖµ

=sin^4x+2(sinxcosx)^2+cos^4x -2(sinxcosx)^2 =[sin^2x+cos^2x ]^2-2(sinxcosx)^2 =1^2-2(sinxcosx)²=1-2(sinxcosx)²=1 ËùÒÔ sinx...

·Ö½âsinXµÄËĴη½+cosXµÄËĴη½

=[(sinX)^2+(cosX)^2]^2-2(sinXcosX)^2={1+sin2X/¡Ì2}*{1-sin2X/¡Ì2}»ò¿É»¯¼òΪ=1-(sin2X)^2/2=1-(1-cos4X)/2/2=(cos4x+3)/4 ½âÎö¿´²»¶®?Ãâ·Ñ²é¿´...

½«f(x)=sinËĴη½+cosËĴη½»¯³É±ê×¼Èý½Çº¯Êý

=(sin²x+cos²x)²-2sin²xcos²x=1²-1/2*(2sinxcosx)²=1-1/2*sin²2x=1-1/2*(1-cos4x)/2=1/4*cos4x...

sin^4x+cos^4x=1,Ôòsinx+cosxµÈÓÚ ÔõôËã,ËãµÃºÃ¼Ó·Ö - °Ù¶È...

ƽ·½µÃ sin^4x+2sin^2xcos^2x+cos^4x=1 ÓÖ sin^4x+cos^4x=1 µÃ sin^2xcos^2x=0 sinxcosx=0 (sinx+cosx)^2 =sin^2x+2sinxcosx+cos^2x =1+0 =1 sinx...

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