求下列週期函數1.y=sin3x/4 x∈R 2.y=cos4x,x∈R

求下列週期函數1.y=sin3x/4 x∈R 2.y=cos4x,x∈R

1.y=sin3x/4 x∈R
T=2π/(3/4)=8π/3
2.y=cos4x,x∈R
T=3π/4=π/2