At first thank you. You have already helped me a lot and the coincidence you demonstrated is clear, but now
i can't understand this:
on a theoretical-physical level I've understood it, I miss the mathematical step
how can i pass from $$\ddot{\theta} + \frac{g}{L} \theta = 0 $$ to $$\theta =...
I've just studied simple pendulum: The simple pendulum (for small oscillations) differential equation is first image.
I've no problem to arrive this result and formula.
My problem is to get to the second formula by passing through another formula (Image 3) that my book mentions. I can't...