Identify the beginning of a sample period for the function: (Please help no one answers my questions)

Question

f (t) = 4sec(3t −6π)

 

a. x=2pi

b. x=1

c. x=2pi/3

d. x=pi

Answer 1

f(t) = 4sec(3t - 6π) = 4/cos(3t - 6π)

 

I am not sure what is meant by the "beginning of a sample period".  If you mean a point where cos(3t - 6π) achieves its maximum, then the maximum value  occurs when cos(3t - 6π) = 1.  One possibility would be 3t - 6π = 0.  So, t = 2π.