I need help on part B. I keep getting it wrong.

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 = where 0 is the angle of elevation of 2y + gt2 the launcher and g is the acceleration due to gravity (32.2 feet/second-). An artilleryman is firing at an enemy bunker located 2575 feet up the side of a hill that is 6250 feet away. He fires a round, and exactly 2.89 seconds later he scores a direct hit. (a) What angle of elevation did he use? 0 = 23.4 0 (Do not round until the final answer. Then round to one decimal place as needed.) Not (b) If the angle of elevation is also given by sec 0 = - y . where Vo is the muzzle velocity of the weapon, find the muzzle velocity of the artillery piece he used. Vo = 2356.58 feet/second (Round to two decimal places as needed.)