Here is everything I've got so far:
I reduced the system to the second order ODE
$$
y_1''+y_1=\frac{1}{\cos x}. \tag{1}
$$
Next steps:
1. Find two linearly independent solutions to the homogeneous equation ##y_1''+y_1=0## --- for instance, ##u(x)=\cos x## and ##v(x)=\sin x##;
2. Compute the...
Yes, I should have mentioned, I already know I should use variation of parameters. However I am not entirely sure which ones and how to apply them. I am fairly confused about it, do you have any tips?
But I don't see how I can solve ##y_1^{\prime\prime}=y_2^{\prime}=-y_1+\frac1{\cos(x)}## using elimination method. Any help? I get the same answer as using https://mathdf.com/dif/, which, according to my professor, is incorrect.
I am trying to solve this system of differential equations using elimination method, but I am stuck.
$$\begin{cases}
y'_1 = y_2, \\
y'_2 = -y_1 + \frac{1}{\cos x}
\end{cases}$$
Here's what I tried:
I've been suggested to differentiate the ##y_1'= y_2## again to get ##y_1''= y_2'=...
I think I posted everything that I've worked so far. The main equation for othogonality is the multiplication of derivatives of the curves equal to minus one, I mentioned it in the post as well. Additionally, I attached the photo where I show my work trying to parametrize the curves, but I'm...
I am asked to prove orthogonality of these curves, however my attempts are wrong and there's something I fundamentally misunderstand as I am unable to properly find the graphs (I have only found for a, but I doubt the validity).
Furthermore, I am familiar that to check for othogonality (based...