How To Setup Swing Party How Do I Solve This Pendulum Problem For Maths?

How do i solve this pendulum problem for maths? - how to setup swing party

Question 2 (Double Pendulum)
Setting: a pendulum of length ℓ suspended
a fixed point and is free of charge in a swing
Aircraft at the end of the pendulum
accompanied by a bob of mass m. For Bob
attached to another string length ℓ
Bob other mass m. The two clocks
Vibration in the xy-plane under the influence
Gravity.

(i) State the y coordinates of each body in the form of θ and φ. With (θ, φ) as coordinates,
find the kinetic and potential energy of the double pendulum, and thus results in the Lagrangian.
This is Lagrange regular basis?
(ii) (a) that the Lagrangian to find the equations of motion for this system.

(b) linearization about the equilibrium (θ, φ) = (0.0), find the normal modes motion
where the angles are very small.
[Note: One way to adapt replacing θ and φ and εθ εφ (θ and ˙ ε ˙ θ, etc.), then
ignoring all terms higher order in ε.]