1.y=sin(x)+cos(x) =根号2*sin(x+π/4)是周期函数,周期为2π2.y=sin^2(x)=(1-cos2x)/2是周期函数,周期为2π/2=π3..y=sin(x)+cos(x/2)是周期函数,周期为4πsin(x+4π)+cos((x+4π)/2)=sin(x)+cos(x/2)...