Iam struggling and need what is 2.3b=36.8 ?

In the past, professional baseball was played at the astrodome in houston, texas. the astrodome has a maximum height of 63.4 m. the height of a baseball t seconds after it is hit straight up in the air with a velocity of 45 ft/s is given by h = -9.8t2 + 45t + 1. will a baseball hit straight up with this velocity hit the roof of the astrodome? use the discriminant to explain your answer.

Find the value of the cosine for angle a

Ijust need to see how to do this. so you don’t have to answer all of them just a step by step explanation of one.