At one instant ,ships X and y are at a distance of d from each other.THe velocities of ship x and ship y are u and v respectively. Angle a and b are acute. Find the tangent of angle betweeen the direction of relative velocity and

My work:

the relative velocity vector is

xVy=Vx-Vy=(u+vsin(a+b))i+(-v cosb)j

relative displacement vector, xRy=(-d)i

Before i proceed with the dot product formulas, can i confirm whether the above is crrect?