solve this please

Q.2. a) What is the difference between the likelihood density function and the a posteriori density function. b) Let x = s + n, where the observed random variable is 'x'. 's' is a random parameter independent of the added random noise 'n'. The probability density of 'n' is given by p(n) = 2 e-2(1-1) u(n - 1) and the probability density of the parameter 's' is given by p(s) = 1/8 s [u(s) - u(s - 4)]. i) Get Sms. ii) Get Smap. iii) Does 's' have a Smi. Why or why not