sinx+siny=3/5,cosx+cosy=4/5,求cos(x-y)sinx^2+cosx^2才＝1啊 不要给我sinx^2+siny^2=1啊 拜托大家帮帮忙老大 过程啊啊啊

sinx+siny=1/3,则siny-(cosx)^2的最大值为?最小值为? 已知sinx+siny=1/3求siny-(cosx)^2的最小值和最大值 已知sinx+siny=1/3求siny-(cosx)^2的最小值 已知sinx+siny=2/3cosx+cosy=2/3,则sinx+cosx的值? sinx+siny=3/5,cosx+cosy=4/5,求cos(x-y)sinx^2+cosx^2才＝1啊 不要给我sinx^2+siny^2=1啊 拜托大家帮帮忙老大 过程啊啊啊 求y=(sinx)^2-cosx+2最值已知sinx+siny=1/3,求siny-(cosx)^2的最值 (sinx-siny)(sinx+siny)-(cosx+cosy)(cosx-cosy)等於? 急!本人赶着数学作业!cosX+sinY=4/5 sinX+cosY=3/5 求sin(x+y) 已知sinx+siny=1/3,cosx-cosy=1/5,求cos(x+y),sin(x-y).求过程! 已知1+cosx-siny+sinx*siny=0,1-cosx-cosy+sinx*cosy=0.求Sinx. 已知1+cosx-siny+sinx*siny=0,1-cosx-cosy+sinx*cosy=0,求sinx的值 已知sinx+siny=1/3,sinx-siny的最小值已知sinx+siny=1/3,sinx-已知sinx+siny=1/3,sinx-siny的最小值是 sinx+siny=2/5,cosx+cosy=6/5,求cos(2x-2y) sinx-siny=-√3/3 cosx-cosy=-1/3 则cos(x-y) sinx-siny=1/3,cosx-cosy=2/3,sin(x+y)=? 已知sinx+siny=√2,cosx+cosy=2√3/3,求tanx*tany cosx+cosy=1/2,sinx-siny=1/3,则cos(x+y)=? cosx-cosy=1/2,sinx-siny=1/3,sin(x+y)=RT