I looked a tiny bit into Tikz because you said it was a "fantastic tool" and i got to say, although it seems very sleek and versatile it also looks a little complicated for a program/language(what exactly is it ?) which just makes graphics.
I guess until i need to make a lot of diagrams, graphics, etc. or a well made one for a presentation i will stick to drawing ugly stuff in paint

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(I am just a eleventh grade student(in germany) right now and not a particularly hard working one at that so please excuse my attitude

)
By the way, you do not have to go through the trouble of putting up a derivation.
I actually think i could do it myself (probably/hopefully) and figuring it out on my own is significantly more rewarding(if i get around to actually doing it).
PS:The formula with the cos psi on one side does not look like its derivation would fit well with my definition of fun

I like math don't get the wrong idea, that formula just looks like it would be tedious to derive.
PPS:This post just makes me seem like i am the laziest person on the planet
