My question is attached below.

Let {X1, X2, . . .XN} be a random sample where each random variable X, has a PDF given by 1 f(x) = ez -(sign(x)+1)(x/2)+(sign(x)-1)(x/#)] ( 2 + ( ) where the sign function is defined as x20 sign(x) = 1-1, 1, x 0, u > 0. In the followings provide complete derivations and explanations of results. a) Find the likelihood function and the log-likelihood function for the parameters 1 , / b) Find Maximum Likelihood (ML) estimators for the parameters 1 , H. c) Determine if these ML estimators are unbiased for N = 1