sinxsin2xsin3x
¡Òsinxsin2xsin3xdx,Çó½â´ð¹ý³Ì
»ý»¯ºÍ²î¹«Ê½:sinx*siny=(1/2)[cos(x-y)-cos(x+y)]sinx*cosy=(1/2)[sin(x-y)+sin(x+y)]sinx * sin2x * sin3x = (sinx*sin2x) * sin3x= (1/2...
Çósinxsin2xsin3xµÄ²»¶¨»ý·ÖµÄ½â´ð¹ý³ÌÈçºÎ?
9£©¡Ò1/(sinx)^2dx=-cotx+c 10£©¡Ò1/¡Ì£¨1-x^2) dx=arcsinx+c
¡Òsinxsin2xsin3xdx RT
sinxsin3x=-(cos4x-cos2x)/2¡Òsinxsin2xsin3xdx=(1/4)¡Òsin4xdx - (1/2)¡Òsin2xcos4xdx=-(1/16)cos4x - (1/4)¡Òcos4xd(...
ÈçºÎÇóº¯Êý f(x) = sinx + sin2x + sin3x µÄÖµÓò...
Ôòf(x)_{max}=f(x_0)=sinx_0+sin2x_0+sin3x_0 2±¶½Ç£¬3±¶½Ç¹«Ê½´úÈëµÃ£º=sinx_0+2sinx_0cosx_0+3sinx_0-4sin^3x_0=2...
ÈçºÎÇó y=sinx+sin2x+sin3x µÄ×îСÕýÖÜÆÚ?
sinxµÄ×îСÕýÖÜÆÚΪ2¦Ðsin2xµÄ×îСÕýÖÜÆÚΪ¦Ðsin3xµÄ×îСÕýÖÜÆÚΪ¦ÐÈýÕßµÄ×îС¹«±¶ÊýΪ2¦Ð£¬Òò´Ë×îСÕýÖÜÆÚΪ2¦Ð
sin3xÔõô»¯Îªsinx - °Ù¶È¾Ñé
1 Ò»¡¢Ð½¨Îĵµ£¬ÊäÈësin3x£¬ÈçͼËùʾ¡£2 ¶þ¡¢Í¨¹ý¹«Ê½sin£¨a+b£©=sinacosb+cosasinb£¬¿ÉÖªsin3x=sin£¨2x+x£©=sin2xcosx+cos2xsinx£¬ÈçͼËùʾ¡£
sinxsin2xsin3xµÄ²»¶¨»ý·ÖÔõôËã?
Çósinxsin2xsin3xµÄ²»¶¨»ý·ÖµÄ½â´ð¹ý³ÌÈçÏ£ºÔËÓù«Ê½£ºsin¦Á¡¤sin¦Â=-(1/2)[cos(¦Á+¦Â)-cos(¦Á-¦Â)]sin2¦Á=2sin¦Ácos¦Á ...
sinxsin2xÔõô»¯¼ò - °Ù¶È¾Ñé
2 È»ºó£¬¸ù¾Ý¹«Ê½sin2x=2sinxcosx£¬µÃµ½sinxsin2x=sinx£¨2sinxcosx£©£¬Èçͼºì¿ò´¦Ëùʾ¡£3 ×îºó£¬¿ÉµÃsinxsin2x=2(sinx )^2 cosx£¬Èçͼºì¿ò´¦Ëùʾ¡£
¡Òsinxsin2xsin3x dxÔõôÇóѽÎûÎû?
¡Òsinxsin2xsin3x dxÔõôÇóѽÎûÎû£¿±¶½Ç¹«Ê½£¬Õ¹Ò»Õ¹ ¸øÄãÕ¹µ½ÕâÍùÏÂÓ¦¸ÃûÎÊÌâÁ˰É
sinxsin2xsin3xÔõô±ä»»µ½(cosx - cos3x)sin3x
ÀûÓûý»¯ºÍ²î¹«Ê½:sinXsin2Xsin3X = -(1/2)(cos3X-cosX)sin3X