The equation y^2 / 9 - x^2 / 16 = 1 represents a hyperbola with its center at the origin (0,0). The foci of a hyperbola are located along the transverse axis, which is the y-axis in this case. The distance from the center to each focus is given by c, where c^2 = a^2 + b^2, and a and b are the lengths of the conjugate and transverse axes, respectively. In this equation, a = 3 and b = 4. Plugging these values into the equation, we get c^2 = 3^2 + 4^2 = 9 + 16 = 25. Therefore, c = 5. Since the foci are located along the y-axis, the coordinates of the foci are (0,5) and (0,-5).