If any of you are struggling to figure out cos and sin, there's a great video on it here(It's ok if you don't understand most of this, it is precalculus)
I think your link is broken. Here:
(btw, isn't this trigonometry and not precalculus?)
Oops! Thanks. And trigonometry is part of pre-calculus
No problem, and oh I see
you thanked someone?