sinx+siny
sinx+siny=
sinx+siny=2sin£û£¨x+y£©/2£ýcos£û£¨x-y£©/2£ý sinx-siny=2cos£û£¨x+y£©/2£ýsin£û£¨x-y£©/2£ý ...
ÈçºÎÇóy= sinx+ sinyµÄµ¼Êý?
·½·¨ÈçÏ£¬Çë×÷²Î¿¼£º
sinX+ sinYµÄ×îÖµ
sinY=sin(90-x)=cosx ÄÇôÔʽ=¸ùºÅ2£¨sinxcos45+cosxsin45)=¸ùºÅ2£¨sin£¨x+45£© £© Òò´Ë×î´óֵΪ¸ùºÅ2£»×îСֵΪ-¸ùºÅ...
Èý½Çº¯ÊýºÍ²î»¯»ýÊÇʲô?
sinx+siny=2sin((x+y)/2)*cos((x-y)/2)¡£sinx-siny=2cos((x+y)/2)*sin((x-y)/2)¡£...
ÏëÎÊһϠsinx¼ÓsinyµÈÓÚsin(x¼Óy)Âð ÕâÀïÁ½¸ö¶¼ÊÇsin...
²»µÈ£¬sinÊÇÕýÏÒº¯ÊýµÄ·ûºÅ¡£sin£¨x+y£©=sinxcosy+cosxsiny sinx£«siny=2sin[(x£«y)/2]cos[(x£y)/2]...
...ÊÇÔõôÓÉsinX+sinYÍƳöºóÃæµÄʽ× ²»ÒªËùνµÄÖ¤Ã÷¹ý³Ì...
??Ö¤Ã÷ºÍÍƵ¼²»Ò»ÑùÂ𣿣¿ÁîX=a+b£¬Y=a-b£¬sinX+sinY=sin(a+b)+sin(a-b)=sinacosb+cosasinb+sinacosb-cosasinb=2sina...
³äÒªÌõ¼þÇósinx+siny=sin(x+ ¨C ÊÖ»ú°®ÎÊ
sinx+siny=sin(x+y) ¡ú2sin[(x+y)/2]cos[(x-y)/2]=2sin[(x+y)/2]cos[(x+y)/2] ¡úsin[(x+y)/2]¡¤[cos((x-y)/2...
ÒÑÖªx>0,y>0,x+y= ¦Ð/2 ,Çósinx+sinyµÄ×î´óÖµ?
sinx+sinyµÄ×î´óֵΪ¡Ì2¡£½â£ºÒòΪx+y=¦Ð/2£¬Ôòy=¦Ð/2-x¡£Ôòsiny=sin£¨¦Ð/2-x£©=cosx£¬ÄÇô...