Hello I am looking at the document:STAT217_SOL5_2013winter number 4. I was wondering if we could go through the steps of that problem. I do not know how to solve that quadratic and how to find the mean. thank you

• Let {Xn} be a branching process with X0= 1. Find the probability of extinction in each of the following situations. Be sure to specify for which values of the variousparameters below extinction is certain.(a) The offspring distribution satisfies, for some 0< p <1,P(= 0) =p ,P(= 2) = 1p