A particle is projected with a velocity u. So that its horizontal range and maximum height reached are equal. The maximum height reached is
2u2/3g
4u2/5g
u2/g
8u2/17g
R=Hmax
2u2sinθcosθg=u2sin2θ2g
tanθ=4
sinθ=417
Hmax=u2.16/172g=8u217g