¡Òsin3xsin5xdxÔõôÇó

ÐëÖª¹«Ê½£ºsinAsinB = (1/2)[cos(A-B)-cos(A+B]¡Òsin(3x)sin(5x) dx = (1/2)¡Ò[cos(-2x)-cos(8x)] dx = (1/2)¡Òcos2x dx - (1/2)¡Òcos8x...


¡Òsin3xsin5xdxÔõôËã

Ê×ÏÈ£¬ÀûÓÃÈý½Çº¯ÊýµÄ³Ë»ý»¯ºÍ²î¹«Ê½£¬½«sin3xsin5xת»¯Îª£º$ frac{1}{2} È»ºó£¬¶Ôת»¯ºóµÄ±í´ïʽ½øÐв»¶¨»ý·Ö£º$ frac{1}{2}intdx ·Ö±ð¶Ôcos8xºÍcos2x½øÐв»...


Çósin^4 xµÄ²»¶¨»ý·Ö?

=¡Ò(1-(1+cos4x)/2)/2dx =(1/4)¡Ò(1-cos4x)dx =x/4-(1/16)sin4x+C


...¡Ò(cosx)^5dx ºÍ¡Òsin3xsin5xdx Ôڴ˸Ðл´ó¼Ò,Çó¸öÏêϸ...

=sinx-2/3*(sinx)^3+1/5*(sinx)^5+C ¡Òsin3xsin5xdx =1/2*¡Ò[ cos2x-cos8x]dx =1/2*¡Ò cos2xdx-1/2*¡Òcos8xdx =1/4¡Ò cos2xd(2x)-1/16¡Ò...


¡Òsinxcosxdx=¡Òsinxdsinx=1/2sin²x+CÀïÃæµÄÔËËã...

cosx µÄÔ­º¯ÊýΪ sinx¼´ ¡Ò cosx dx =¡Ò d(sinx) ´øÈëÔ­·½³ÌÓÐ:ԭʽ=¡Òsinx d(sinx) Ï൱ÓÚ ¡Òx dx= x^2+C ´øÈëÓÐ=1/2sin²x+C


¡Òsin3xsin5xdx Õâ¸öÔõôËã?

¡Òsin3xsin5xdx =-(1/2)¡Ò(cos8x-cos2x)dx =-(1/2)((1/8)sin8x-(1/2)sin2x)+C =(-1/16)sin8x+(1/4)sin2x+C Óв»Ã÷°×µÄµØ·½ÔÙÎÊÓ´£¬×£Äãѧϰ...


·Ö²¿»ý·Ö·¨Çó¡Òx^2sin^2xdx,¡ÒIn^2xdxÒª¹ý³Ì

¡Òx²sin²x dx=(1/2)¡Òx²(1-cos2x) dx=(1/2)¡Òx² dx - (1/2)¡Òx²cos2x dx=(1/2)(1/3)x³ - (1/2)(1/2...


Çósin3xsin5x Ô­º¯Êý,Çó1/[(sinx)^4+(cosx)^4]µÄÔ­º¯Êý...

¡Òsin3xsin5xdx = (1/2)¡Ò(cos2x-cos8x)dx (ÓÃÁË»ý»¯ºÍ²î£©= (1/2)[(1/2)sin2x-(1/8)sin8x]+C = sin(2x)/4-sin(8x)/16+C.(sinx)^4+(cosx...


¡Ò(sin3xsin5x)dx

¡Ò(sin3xsin5x)dx °Ù¶ÈÍøÓÑ531ceaa530


...µ±ÖпÉÒÔ½«Ô­Ê½ÖеÄsinx»»³ÉtÂð?sinxsin2xsin3x...

²»¶¨»ý·Öµ±ÖпÉÒÔ½«Ô­Ê½ÖеÄsinx»»³ÉtÂð£¿sinxsin2xsin3xÈçºÎÀûÓÃsinx»¯½â£¿Áîy=cosx+isinx(x¡ÊR)(1)Ôòdydx=sinx+icosx ...


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