Can anyone help please =)?

Look at the following graph of the given equation. determine whether the equation is a function. explain why or why not.

Describe the 2 algebraic methods you can use to find the zeros of the function f(t)=-16t^2+400.

1jessica's home town is a mid-sized city experiencing a decline in population. the following graph models the estimated population if the decline continues at the same rate. select the most appropriate unit for the measure of time that the graph represents. a. years b. hours c. days d. weeks