Time period of a double pendulum for SMALL ANGLES

I am currently writing up my physics coursework - my experiment was changing the mass and length ratios of a double pendulum and measuring how the time period is affected. I am looking at small angles of release so the motion isn't really chaotic. I can't find any formula for the time period of a double pendulum on the internet though, can anyone help?

I've never actually tried this... but could you calculate what the period for a simple pendulum with the same CoG as your double pendulum when it's in it's equilibrium position is, and then show whether or not your double behaves the same as that?

FWIW there's a discussion of double pendulums in Ian Stewart's book 'Does god play dice?' which you could probably borrow from a town library.

I all ready tried that and there was no similarities. :/

well a negative result is still a result.

tbh I think your teacher should have steered you away from this investigation as the maths you need to model the system is undergraduate level.

Haha, he actually suggested it! But yeah I have seen the maths behind trying to model the motion . Well I have a relationship to talk about I just can't say what exactly effects the time period. Thanks for your help anyway, I was just wondering if there was a simple equation but it appears not.