I was given the following problem to graph:

y=3sec(2(x-pi))-3

I know the amplitude is 3 and the period is pi and the vertical shift is 3 down, but is the phase shift Pi or Pi/2?

Because if it is Pi/2 the graph of cosine starts at -3....which would contradict the amplitude being 3. And if it is Pi that would mean the phase shift is from Pi to Pi so there would be no shift...