(a) The vertex is \(\left( \frac{1}{2}, -\frac{5}{2} \right)\)
{"axisType": 3, "coordSystem": {"xmin": -3, "xmax": 3, "ymin": -5, "ymax": 1}, "commands": ["y = -(1/3)*(x-(1/2))**2 - (5/2)"], "latex_expressions": ["$f(x) = -\\frac{1}{3}\\left(x-\\frac{1}{2}\\right)^{2}-\\frac{5}{2}$"]}