f(sin^4x+cosx)dx=

I(2n)=¡Ò (sinx)^(2n) dx=-¡Ò (sinx)^(2n-1) dcosx=-cosx.(sinx)^(2n-1) +(2n-1).¡Ò (sinx)^(2n-2).(cosx)^2 dx=-cosx.(sinx)^(2n-1) +(...


²»¶¨»ý·Ösinxcosx/1+sin4x dx

²»¶¨»ý·Ösinxcosx/1+sin4x dx huamin8000


Çó|sinxcosx|/1+sin^4xÕâÒ»º¯ÊýµÄÖÜÆÚ

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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,...


²»¶¨»ý·ÖÌâÇósinxcosx/1+sin^4xµÄ»ý·Ö

¡Ò sinxcosx/(1 + sin⁴x) dx= ¡Ò sinx/(1 + sin⁴x) dsinx= (1/2)¡Ò 1/[1 + (sin²x)²] dsin²x= (1/2)arctan(...


º¯Êýy=sin(4´Î·½)x+cos(4´Î·½)xµÄ×îСÕýÖÜÆÚÊÇ?

y=(sinx)^4+(cosx)^4=[(sinx)^2+(cosx)^2]^2-2(sinx)^2(cosx)^2=1-(1/2)[sin(2x)]^2=1-(1/4)2[sin(2x)]^2=1/4-(1/4)2[sin(2x)]^2+...


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¡Òsinxsin2xsin3xdx,Çó½â´ð¹ý³Ì

* sin3x = (1/2)(sin3x*cosx) - (1/2)(sin3x*cos3x) = (1/2)*(1/2)[sin(3x-x)+sin(3x+x)] - (1/2)(sin3x*cos3x) = (1/4)(sin2x+sin4x) - (...


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