19-18-17-16-15-14-13-12-11 -10 -9 -8 -7 -6 -5 -4 -3 -2 -1 4- 2 1 3 4 5 6 7 9 -1 -2+ -3- -4- -5+ The curve above is the graph of a sinusoidal function. It goes through the points (-9,-4) and (5,-4). Find a sinusoidal function that matches the given graph. If needed, you can enter =3.1416... as 'pi' in your answer, otherwise use at least 3 decimal digits. f(x) =