how do you find phase shift of something when you are only given the data but no the graph?

Question

the question says: determine the phase shift for your curve. remember that t=0 is midnight at the start of the first day, and that a cosine curve starts at the maximum value. it is not just the first time difference that you count as the phase shift.

Answer 1

P.S = -c/b

I'm assuming that you are talking about the trig. fun.

So the is the formula to do so.