Çóxdy/dx+y=sinxµÄͨ½â

xdy/dx+y=sinx y'+y/x=sinx/x È»ºó´ú¹«Ê½ Ò»°ãÇé¿öÏ£ºy'+p(x)y=q(x)ÄÇôÆä½âµÄ¹«Ê½Îª£ºy=e^[-¡Òp(x)dx]{¡Òq(x)*e^[¡Òp(x)dx]dx+C} =e^[-...


xdy/dx+2y=sin x,Çóͨ½â

½â£º¡ßxdy/dx+2y=sinx ==>xdy+2ydx=sinxdx ==>x^2dy+2xydx=xsinxdx ==>d(x^2y)=xsinxdx ==>¡Òd(x^2y)=¡Òxsinxdx ==>x^2y=sinx-xcosx+C (C...


ÔõôÅж϶þÖØ»ý·ÖÊÇxÐÍ»¹ÊÇyÐÍ?

½âÌâ¹ý³ÌÈçÏ£ºDsinxydxdy=¡Ò12dy¡Òyy3sinxydx=¡Ò12(ycosxy)|yy3dy=¡Ò12(ycosy2+ycos1)dy=12(3cos1+sin1sin4)...


΢·Ö·ûºÅ,dx,dyµ½µ×ÊÇʲôº¬Òå?

¸Õѧ¸ßÊý£¬ÓõÄͬ¼Ã½Ì²Ä£¬Ñ§µ½Òþº¯ÊýÇóµ¼µÄʱºò£¬½Ì²ÄĪÃûÆæÃîµÄ³öÏÖdy£¬dx £¬d/dyµÈ·ûºÅ£¬´Ëºó½Ì²Äµ¼ÊýÈ«ÓÃdʲôdʲô±íʾÁË£¬½Ì²ÄûÓжÔ...


Çó´Ëº¯ÊýµÄ΢·Ö y=sinxy

y=sin(xy)dy=d(xy)*cos(xy)=(ydx+xdy)cos(xy)dy-(xcos(xy))dy=ydxdy=y/[1-xcos(xy)] dx


Ò»µÀÄÑÌâ,Çóѧ°ÔÖ¸µã,лл

µÃ£ºxdy=(sinx-y)dx ¶ÔÁ½±ßͬʱ»ý·Ö£º¡Òxdy=¡Ò(sinx-y)dx ½âµÃ£ºxy=-cosx-xy+C (CΪ³£Êý)ËùÒÔy=(C-cosx)/2x ºÜÀÖÒâ°ïÖúÄ㣬Çë...


xdy+(y+sinx)dx=0µÄͨ½â

½â£º¡ßxdy+(y+sinx)dx=0 ==>(xdy+ydx)+sinxdx=0 ==>¡Ò(xdy+ydx)+¡Òsinxdx=0 ==>xy-cosx=C (CÊÇ»ý·Ö³£Êý)==>y=(cosx+C)/x ¡à´Ë·½³ÌµÄͨ½âÊÇy=(...


¸ßµÈÊýѧ Çóͨ½â

¡ßxy¡ä£«y£½sinx£¬¡àxdy£«ydx£½sinxdx£¬¡àd£¨xy£©£½£­d£¨cosx£©¡àxy£½£­cosx£«C¡£¡àԭ΢·Ö·½³ÌµÄͨ½âÊÇ£ºxy£½£­cosx£«C¡£y


΢»ý·ÖxdyµÈÓÚ¶àÉÙ

3¡¢¡Ò 1/x dx = ln|x| + C 4¡¢¡Ò a^x dx = (1/lna)a^x + C£¬ÆäÖÐa > 0 ÇÒ a ¡Ù 1 5¡¢¡Ò e^x dx = e^x + C 6¡¢¡Ò cosx dx = sinx +...


...=C1sinx+C2sinx,(C1,C2ΪÈÎÒâ³£Êý)(2)(x+y)dx= - xdy...

(1)¡ßy=C1sinx+C2sinx¡ày'=C1cosx+C2cosxy''=-C1sinx-C2sinx=-y==>y''+y=0¡ày=C1sinx+C2sinxÊÇy''+y=0µÄ½â¡ß·½³Ìy''+y=0ͨ½âÊÇy=Asinx+Bcosx (A,...


Ïà¹ØËÑË÷

ÈÈÃÅËÑË÷