Hi everyone

I really dont know how to start this questions, please help me. Thank you in advance for all your help & support.

Determine if each of the following CT signals is periodic. If periodic find it period.

a) x(t)=2sin(10 t-30degrees)

b) x(t) = 2 cos ( 2 t)

c)x(t) = 2 sin ( t)

d) x(t) = 2 cos (t+ 60degrees)