Isn't this already a pmf?
The distribution of a random variable X is given by
Determine the probability mass function of X.
I have no idea where to begin. Can anyone show the process to determine the probability mass function so that I can repeat it for other problems?
Well, I didn't think so. But I'm not sure. I don't see why my textbook would have asked for the pmf if it was one already. My understanding was that this was the distribution function and the pmf could be gotten from this function. However, I could very well be wrong.