Please all show steps. I'm having problem doing the calf by hand.

b) Independence (10 Points) Question 4 (5 Points). (1) [1 pt] If two random variable Y1 and Y2 are independent. Then, we need what condition to be satisfied? (ii) [4 pts] Refer back to question 2 - are the random variables Y, and Y2 independent? Question 5 (5 Points). Let X, and X2 have a joint density given by: 0, elsewhere are the random variables X, and X2 independent? c) Covariance and Other Topics (10 Points) Question 6 (5 points). Using the joint density found in Question 5, compute the covariance of X, and