Let X be a random variable whose probability mass function is given by

px(x)=0.5 when x=-1

px(x)=0.2 , x=0

px(x)=0.3, x=3

1) Find Distribution Function of X

2) We define Y=X^(2)+X+1 , Find probability mass function of Y

3) Calculate Mathematical Expictation of X^(3)