This is a behind the scenes video (Simon wasn’t even aware of me filming at first, but he always talks to himself when working out a proof, so that helps). The video shows Simon looking for the number *z* if *sin(z)* = 2. He watched this problem explained on the Blackpenredpen channel once, then marched into another room (where he has his whiteboard) and started trying to construct the solution on his own. His solution was partially based on what he saw in the working out shown by Blackpenredpen and partially he worked out the proof himself (and it just happened to coincide with that of Blackpenredpen). He only briefly consulted the explanation video three times while working on the proof. “My proof expanded some steps out so it’s clearer where I’m coming from,” Simon says.

Here is a picture of the work done:

And some pics of the working out in progress:

Simon at first made a mistake in his definition of *ln(i)*:

But later he corrected himself, and that’s the part you can see in the video.