The profit P (in millions of dollars) for a recreational vehicle is modeled by a quadratic function of the form
P = at2 + bt + c, where t represents the year.
If you were the president of the company which of the models below would you prefer? Explain your reasoning and provide all calculations to support your response.
a) a is positive and -b/(2a) < t
b) a is positive and t < -b/(2a)
c) a is negative and -b/(2a) < t
d) a is negative and t < -b/(2a)