Write an expression for the tax revenue in terms of t t is

Question

On a particular product, government economists determine that the relationship between tax rate t and the quantity consumed q of the product is given by

t=18-3q².

1. Write an expression for the tax revenue in terms of t (t is expressed in percent).
2. Treating t as your choice variable, maximize this tax revenue function to find the optimal tax rate for the government. (Be sure to check your second-order condition.)