19-18-17-16-15-14-1312-11-10 -9 -8 -7 -6 -5 4-3-2-1 -1 -2 The curve above is the graph of a sinusoidal function. It goes through the points (9, 3) and (5,-3). Find a sinusoidal function that matches the given graph. If needed, you can enter T =3.1416... as 'pi' in your answer, otherwise use at least 3 decimal digits.