I have been asked to find an equation with the subject of V (initial speed) with only the information given, angle above horizontal, range, and initial height above ground. I did attempt this myself and got the formula:

v = initial speed

θ = initial angle

s = range (total)

h = initial height above ground

v

^{3}(2s*tanθ) + v

^{2}(2h) +

^{s2}/

_{cos2θ}= 0

It is a cubic and so I left it in this form but I found this to be incorrect (will not show working as it is around a page) and have been over my work multiple times. Please help me with this!