Hi could someone please help me on the following problem:

f(x) = {sin x, -2pi less than or equal to pi less than 0

{cos x, 0 less than or equal to x less than or equal to 2 pi

a) Draw the graph of f

b) At what points c in the domain of f does lim x approaching f(x) exist?

c)At what point does c does only the left-hand limit exist?

d)At what points c does only the right hand limit exist?

Thank you.