Hinged rod attached to elastic string

[adam640]

A rod (mass M, length L) hinged at point X. End Y is attached to X by an elastic string passing over a pin P, the natural length of the string is L. P is a distance L from X.

Elastic Modulus of string: (1/4Mg)

Refer to GPE to X and prove that total PE is: (1/4)MgL(1-cosθ-2sinθ) and find angle θ for the equilibrium position.

http://img155.imageshack.us/img155/1247/47349211.png

I literally have no idea where to begin with this and any help at all would be greatly appreciated.

Thank you in advance.

 

[rude man]

How about summing torques about X to zero?

And then maybe an apposite trigonometric identity?