The function f is periodic, with period c. So, f (t + c) = f (t). Determine whether each statement is true or false. Explain.
a. f (t − 2c) = f (t)
b. f(t + 1 / 2c) = f (1 / 2t)
c. f (1/2 [t + c]) = f (1/2t)
d. f (1/2[t + 4c]) = f (1 / 2t)