A particle is projected with an angle of projection θ to the horizontal line passing through the points (P,Q) and (Q,P) referred to horizontal and vertical axes (can be treated as x-axis and y-axis respectively). The angle of projection can be given by?

The correct option is A tan⁻¹[P²+PQ+Q²/PQ]
The general equation of path for projectile motion is
y=xtanθ-gx²/2u²(cosθ)²
Now since the above equation passes through (P,Q) and (Q,P) so we will get two equations as
P=Qtanθ-gQ²/2u²(cosθ)² (1)
Q=Ptanθ-gP²/2u²(cosθ)² (2)
Solving equation 1 and 2 simultaneously we get
θ=tan⁻¹[P²+Q²+PQ]/[PQ]