Imagine we toss a fair coin. Let X = 1 if the coin shows heads; let X =0 when it shows tails. What is the probability mass function?

Question

anonymous · Answer

Is it f(x) = x^2?

welshfella · Answer

statistics is not my strong point this link will help:- https://en.wikipedia.org/wiki/Probability_mass_function

hartnn · Answer

PMF is a function which gives you the probability that the random variable takes a particular value.

Here, X is your random variable.
so what is the probability that X= 1 ??
means what is the probability that a fair coin toss shows HEAD? 

similarly, 
what is the probability that X= 0 ??
means what is the probability that a fair coin toss shows TAILS?

what is the probability that X takes any other value??

Based on your answers of the above questions, we can make PMF.