Which relation is a function?

Joe has some money in his bank account he deposits 45$ write an expression that represents the amount of money in joe's account

What is the probability of throwing several dice with sum equal to 6 (six)? show the ways of possibilities for sum 6 (as the numerator) and the ways of throwing n dices for n = 1, 2, 3, 4 or 5 as denominator for all the questions to earn full credits. (a)throw one die, (b) throw two dice, (c) throw three dice (d) throw 4 dice, (e) throw 5 dice

Cos^2x+cos^2(120°+x)+cos^2(120°-x)i need this asap. pls me