(i) When the angle of projection, θ = 45o + α , the horizontal range is
\(R=\frac{u^2\,sin\,2\,(45^0+\alpha)}{g}\)
= \(\frac{u^2sin(90^0+2\alpha)}{g}\)
= \(\frac{u^2\,cos\,2\alpha}{g}\)
(ii) When the angle of projection, θ = 45o – α, the horizontal range is
Clearly, R' = R