I need help on this question

A projectile fired into the first quadrant from the origin of a coordinate system will pass through the 2x point (x,y) at time t according to the relationship cot 0 = 2y + gt 2 where 0 is the angle of elevation of the launcher and g is the acceleration due to gravity (32.2 feet/second"). An artilleryman is firing at an enemy bunker located 2525 feet up the side of a hill that is 6500 feet away. He fires a round, and exactly 2.27 seconds later he scores a direct hit. . . ... (a) What angle of elevation did he use? 0 =0 (Do not round until the final answer. Then round to one decimal place as needed.)