ce amaths---rate of change

19. OA is a moving rod and OB is a fixed platform. OP and PQ are two rigid parts with OP=√3 m and PQ=5/2 m.As A rototes around O, Q moves towards O along OB. lET ∠POQ=θ and OQ=x m (x＞0)
a) Find x when θ=π/3 radians.
b) If the rate of change of ∠POQ with respect to time is 2 radians/second, find the rate of change of OQ with respect to time when θ=π/3 radians.