cos(x+y)sinx-sin(x+y)cosx
cos(x+y)sinx-sin(x+y)cosx
sinx*sin(x+y)+cosx*cos(x+y)等于?
化简sin(x+y)sinx+cos(x+y)cosx等于?
化简sin(x+y)sinx+cos(x+y)cosx
化简cos(x+y)sinx-sin(x+y)cosx
y=cosX,y= - cos(-X) 与y=sinX,y= - sin(-X) 为什么?
为什么y=sinx,y=-sin(-x)=sinx,y=cosx,y=-cos(-x)=-cosx
函数y=cosx/√(1-sin²x)+√(1-cos²x)/sinx的值域?
函数y=√(1-sin²x)/cosx+√(1-cos²x)/sinx的值域是
请问怎么证明sinX+sin(X+Y)+sin(X+2Y)/cosX+cos(X+Y)+cos(X+2Y)=tan(X+
求证:sin(x-y)/(sinx-siny)=cos[(x-y)/2]/cos[(x+y)/2]
y=sin²X+2sinX*cosX+3COS²X的最大值是?