求下列函数的周期: (1)y=sin2/3x,x∈R; (2)y=1/2cos4x,x∈R.

问题描述:

求下列函数的周期:
(1)y=sin

2
3
x,x∈R;
(2)y=
1
2
cos4x,x∈R.

(1)∵y=sin

2
3
x,
∴T=
2
3
=3π;
(2)∵y=
1
2
cos4x,
∴T=
4
=
π
2