You should be able to do the domain and range of these functions easily.

Otherwise

is the (almost) most general form for the cosine function, where A is the amplitude. The period P of this function can be obtained by setting x = P:

The x intercept(s) should also be fairly easy. For what x values does cos(x) become 0?

For the y intercept simply input x = 0 into your equation.

-Dan