Can someone tell me the answer to this please???

Is each relation a function? if so, state whether it is one-to-one or many-to-one. 3. (-4,7), (-3,5), (1,4), (3,-8), (5,-11) 4. (-4,8), (-2,4), (0,1), (2,4), (4,8) 5. (-2, 1), (-2,3), (0,-3), (1,4), (3,1)

Express the following as a function of a single angle. cos(60) cos(-20) - sin(60) sin(-20)

The function f(x) = 14,600(1.1)* represents the population of a town x years after it was established. what was the original population of the town?