Linearization of nonlinear differential equations

[Fenrir13]

Hello everyone, i have a non-linear system but i don't know how i can linearize it.
I want to linearize it aroun theta1 = 0 and theta2 = 0, i know that sen(theta) = theta and cos(theta) = 1, but this is still a nonlinear differential equation, due to the terms w1^2 and w2^2, thanks for reading.

 

[onatirec]

Have you tried a taylor series expansion around theta1=theta2=0? That would always be the first tool we'd reach for in physics to linearize...