如果cosx+cosy-cos(x+y)=1.5,x,y为锐角,求x和y.

来源：学生作业帮助网 编辑：作业帮 时间：2024/07/04 01:10:48
如果cosx+cosy-cos(x+y)=1.5,x,y为锐角,求x和y.
xPN0~bǍ [H !KH**6t*?[xIxD|}>?f9+Oχ#G2Xm깇0?no6),߳DL'O.^:3w(! NmrsÄ0DHk(53쐌z7hN/Ճb@ I͔*/ gnR|!-|W&8- @uW:͌ tP,hfju{妁-b׎@^º(?A&@^mQR ,+V&Y

如果cosx+cosy-cos(x+y)=1.5,x,y为锐角,求x和y.
如果cosx+cosy-cos(x+y)=1.5,x,y为锐角,求x和y.

如果cosx+cosy-cos(x+y)=1.5,x,y为锐角,求x和y.
cosx+cosy-cos(x+y)=3/2
--->2[cos(x+y)/2]^2-2[cos(x+y)/2][cos(x-y)/2]+1/2=0
[-2cos(x-y)/2]^2-4>=0
--->[cos(x-y)/2]^2>=1
[cos(x-y)/2]^2=1
x、y(0,兀) --->(x-y)/2(-兀/2,兀/2).
x=y,
x=y=兀/3.

cosx+cosy-cos(x+y)=1.5
式中x,y轮换对称，所以X Y 相等。
X =Y代入
2cosX-cos(2X)=3/2
2cosX-(2(cosX)^2 -1)=3/2
2(cosX)^2 -2cosX +1/2 =0
(cosX -1/2)^2 =0
cosX=1/2
X =π/3
所以，X =Y =π/3

如果cosx+cosy-cos(x+y)=1.5,x,y为锐角,求x和y. 如果cosx+cosy-cos(x+y)=0,x,y为锐角,求x和y. 三角函数题cosx+cosy=cosxcosy……cosx+cosy=cosxcosy,cos((x+y)/2)=0.8,则cos((x-y)/2)=? 若cos(x+y)cosy+sin(x+y)siny=0,则cosx= 若cosx*cosy+sinx*siny=1/3 ,则cos(2x-2y)=? 已知cosx+cosy=1/2,sinx-siny=1/3,求cos(x+y) cosx+cosy=1/2,sinx-siny=1/3,则cos(x+y)=? cosx-cosy=4/1,sinx-siny=3/1求cos(x-y) sinx+siny=2/5,cosx+cosy=6/5,求cos(2x-2y) 已知cosx+cosy=1/2,sinx-siny=1/3,则cos(x+y)= 已知sinx+siny=0.4,cosx+cosy=1.2,求cos(x-y) sinx-siny=-√3/3 cosx-cosy=-1/3 则cos(x-y) cos(x+y)不等于0,cosx*cosy也不等于0吗 sinx+siny+sinz=0;cosx+cosy+cosz=0;求cos(x-y) sinX+sinY=1 cosX+cosY=0 求cos(2X)+cos(2Y)的值 已知sinx+siny=1/3,cosx-cosy=1/5,求cos(x+y),sin(x-y).求过程! 已知cos(x-y)cosx+sin(x-y)sinx=3/5,则cosy的值为 COSX+COSY-COS(X+Y)=3/2求角X Y分别是多少?谢谢好心的师姐师兄啦.