siny=1/3,sin(x＋y)=1,求sin(2x＋y)

来源：学生作业帮编辑：作业帮分类：数学作业时间：2024/05/26 20:45:26

sin(x＋y)=1 所以可得：cos(x+y)=0
sin(2x+2y)=2sin(x+y)cos(x+y)=0
cos(2x+2y)=cos^2(x+y)-sin^2(x+y)=-1
siny=1/3 所以可得：cosy=±√[1-sin^2y]=±2√2/3
当：cosy=2√2/3 时有：
sin(2x+y)
=sin(2x+2y-y)
=sin(2x+2y)cosy-cos(2x+2y)siny
=-2√2/3
当cosy=-2√2/3 时有：
sin(2x+y)
=sin(2x+2y-y)
=sin(2x+2y)cosy-cos(2x+2y)siny
=2√2/3

已知x-y=派/3,且sin x-siny=1/2,求cos(x+y). sinx+siny=-1/3 cosx+cosy=1/2,求sin(x+y)的值. 证明sin(x+y)sin(x-y)=sinx-siny 已知x,y,z属于(0,派/2),sin^2x+sin^2y+sin^2z=1,求(sinx+siny+sinz)/(c 证明sinx+siny+sinz-sin(x+y+z)=4sin((x+y)/2)sin((x+y)/2)sin((x+ 已知sinx-siny=1/2,cosx-cosy=1/2,x、y均为锐角,求sin(x-y) 已知sinx+siny=1/3,cosx-cosy=1/5,求cos(x+y),sin(x-y). 求函数z=sinx+siny+sin(x+y)(0 求sin(x+y)=sinx+siny的导数 sinx+siny=1/2,cosx+cosy=（根号3）/3,求sin[(x-y)/2] 求下列导数：sin(x+y)=sinx+siny e^x+x=e^y+y 证明sin(x+y)sin(x-y)=（sinx）^2-(siny）^2.