Help with Second order differential equation

DogeTheBeast

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I am a class 12 student who is researching in physics. During the process of modeling a trebuchet, I used Lagrangian mechanics for it. And through the Euler lagrangian equation, I landed upon 2 second order differential equations. The theta and the alpha are functions of time. I have no experience with differential equations. Any inputs will be helpful. All the other variables are constants which i plan to add later.
[MATH]mgl_2sin( θ ) - mgl_3sin( θ-α )- Mg l_1 sin( θ ) - [m l_2^2 \ddot{ θ } + ml_3^2 ( \ddot{θ} -\ddot{α} )+m l_2 l_3 \dot{ α} ( 2 \dot{θ} - \dot{α} ) sin( α ) -m l_2 l_3( 2 \ddot{θ} - \ddot{α} ) cos(α )+ M l_1^2 \ddot{ θ }] = 0[/MATH]

[MATH] m l_2 l_3 \dot{ θ }( \dot{θ} - \dot{α} ) sin (α ) + mgl_3 sin(θ -α ) +ml_3^2( \ddot{θ} - \ddot{α} ) - ml_2 l_3 \ddot{θ } cos( α) + ml_2 l_3 \dot{ θ } \dot{ α }sin ( α ) = 0 [/MATH]
 
I am a class 12 student who is researching in physics. During the process of modeling a trebuchet, I used Lagrangian mechanics for it. And through the Euler lagrangian equation, I landed upon 2 second order differential equations. The theta and the alpha are functions of time. I have no experience with differential equations. Any inputs will be helpful. All the other variables are constants which i plan to add later.
[MATH]mgl_2sin( θ ) - mgl_3sin( θ-α )- Mg l_1 sin( θ ) - [m l_2^2 \ddot{ θ } + ml_3^2 ( \ddot{θ} -\ddot{α} )+m l_2 l_3 \dot{ α} ( 2 \dot{θ} - \dot{α} ) sin( α ) -m l_2 l_3( 2 \ddot{θ} - \ddot{α} ) cos(α )+ M l_1^2 \ddot{ θ }] = 0[/MATH]

[MATH] m l_2 l_3 \dot{ θ }( \dot{θ} - \dot{α} ) sin (α ) + mgl_3 sin(θ -α ) +ml_3^2( \ddot{θ} - \ddot{α} ) - ml_2 l_3 \ddot{θ } cos( α) + ml_2 l_3 \dot{ θ } \dot{ α }sin ( α ) = 0 [/MATH]
You say:

I have no experience with differential equations.

If that is the case - how do you plan to solve these non-linear DEs? Have you taken any classes regarding solution of DE?

Please show us what you have tried and exactly where you are stuck.

Please follow the rules of posting in this forum, as enunciated at:

https://www.freemathhelp.com/forum/threads/read-before-posting.109846/#post-486520

Please share your work/thoughts about this assignment.
 
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