n***p
发帖数: 7668 | 1 OK, 闲着也是闲着，赚个包子吧。
a sinx +b sin(x+m)
= a sinx + bsinx cosm + bcosx sinm
= (a+bcosm)sinx + bsinm cosx
= c sin(x+n)
where
c =sqrt( (a+bcosm)^2 + (bsinm)^2 )
=sqrt( a^2 +b^2 +2abcosm)
And we need to take n so that
cos n = (a+bcosm) /c
sin n = bsinm /c. |
|
