A line segment is formulated by the equation y=x+b Where x, y are variables and b is a given parameter, x E [0, l], i.e. x can take on a range of values between 0 and 1. (a) How can you tell if the above line segment is a probability distribution function (PDF)? (3 marks) (b) What is the value of I) such that the above line segment is a PDF? (7 marks)