已知y=3sin(x+20)+5sin(x+80),求最大值?

已知y=3sin(x+20)+5sin(x+80),求最大值? 已知y=3sin(x+20)+5sin(x+80)求最小值如题 已知sin(x+y)=1/3,sin(x-y)=1/5,则tanx/tany 已知y=3sin(x+20°)+5sin(x+80°）,求该函数最大值 已知sin(X+Y)=2/3,sin(X-Y)=1/5,求(tanX)/(tanY)的值 已知sin(x+y)=2/3,sin(x-y)=2/5,则tanx/tany的值是多少? 已知sinx=1/3,sin(x+y)=1,则sin（2y+x)= 函数y=3sin(x+20)+5sin(x+80)的最大值 函数Y=3sin(x+20度)+5sin(x+80度)的最大值? 已知sinx=3/5,x∈(π/2,π),求【sin(x+y)+sin(x-y)】/【cos（x+y）+cos（x-y）】的值 matlab中一些新手问题,syms x y;y =ezplot('1/5*(-2-5/(-125+100*sin(x))*(-20*sin(x)+40+10*(-121*sin(x)^2-100*sin(x)+121+100*sin(x)^3)^(1/2))+5/2*sin(x)/(-125+100*sin(x))*(-20*sin(x)+40+10*(-121*sin(x)^2-100*sin(x)+121+100*sin(x)^3)^(1/2)))*cos(x) 已知5siny=sin(2x+y),求证:tan(x+y)=3/2tanx 已知sin(x-y)cosx-cos(x-y)sinx=3/5求tan2y的值 已知sin(x-y)cosx-cos(y-x)sinx=3分之5,y是第三象限角,求sin(y+5π分之4）的值 已知Sin(x+y)Cosx-Cos(x-x)Sinx=3/5求tan2y的值 已知Sin x+Sin y=1/2,Cos x+Cos y=根号3/3,求S求Sin(x-y)/2 已知x+y+z=π,证明sin(x+y)+sin(y+z)+sin(z+x)≥sin2x+sin2y+sin2z 已知sin(x+π/6)=1/3,求sin(5π/6-x)+sin^2(π/3-x)