Solve the Problem $y = ( \tan \theta ) x - \frac { 16 } { v ^ { 2 } \cos ^ { 2 } \theta } x ^ { 2 }$

Multiple Choice

Solve the problem.
-The altitude of a projectile in feet (neglecting air resistance) is given by $y = ( \tan \theta ) x - \frac { 16 } { v ^ { 2 } \cos ^ { 2 } \theta } x ^ { 2 }$ where x is the horizontal distance covered in feet and v is the initial velocity of the projectile at an angle θ from the horizontal. Find the firing angle (in degrees) of a projectile fired at an initial velocity of 100 feet per second so
That it strikes the ground 312.5 feet from the firing point.

A) 30°
B) 45°
C) 50°
D) 22.5°