HP Prime - Brain Teaser

[CR Haeger]

Okay, maybe I can nudge things along...

Numerical solution(s) can be obtained for this question using the Solver App and these equations:

xt=v0*COS(θm)*t
yt=-(1/2*g*t^2)+v0*SIN(θm)*t

where θm is launch angle. I didn't use θ, which is a predefined Home Real var, since I wanted ot use these equations later in CAS...

If you tried using this App, did you run into any issues? Any other solution methods used?

Best,
Carl