Test the f(x) values incrementally, to get a rough idea on the structure of the graph.
If this is between [0, ], test:
0, , , , , , , , .
Given that the frequency of the cosine function is 12, you may want to do , , etc as well..
Essentially, do what you did in high school when you first learnt how to graph linear equations, have a row of values for x, and a row for f(x).
Of course, there is always Wolfram|Alpha; it can give you some guidance.
sin(x)cos(12x) - Wolfram|Alpha