If 1+ cos2a = 3 sin a cos a，cos a=/0 ，find tan a

Solve the equation 3x2 + 19x + 9 = 0 to the nearest tenth.

Tom wants to order tickets online so that he and three of his friends can go to a water park the cost of the tickets is 16.00 per person there is also a 2.50 one-time service fee for ordering tickets online write an expression in term of n that represents the cost for n ordering tickets online

Find the solution set of this inequality. enter your answer in interval notation using grouping symbols. |8x-4| ≤ 12