Maria has a business designing and making custom T-shirts. Her cost for materials, in thousands of dollars, is given by M(t)=−3 t 2 +36t M ( t ) = − 3 t 2 + 36 t , where t t is the number of the month (1-12) on the last day of the month. Her income from sales is given by S(t)=−4 t 2 +48t S ( t ) = − 4 t 2 + 48 t . What is the function P(t) P ( t ) that gives her profit as a function of time? Hint: Profit equals the difference of the income and the cost.