QUOTE(Raijinili @ Oct 9 2010, 05:11 PM)

QUOTE(Elnendil @ Oct 8 2010, 10:53 AM)

"Are you explaining divisibility to me? I was clarifying that it's not something you have to prove, because it's basically the definition."
Yeah but it doesn't hurt to clarify.
Clarify what...?
Even definitions have proofs. I'm going to drop this since its going nowhere.
QUOTE
QUOTE(Elnendil @ Oct 9 2010, 02:34 PM)

Last night when there were some quiet moments I skimmed through my Trigonometry book, since, well, lets say the Professor that taught me was hard to follow. Very very hard to follow. Example: A few days ago I wondered why sinx/cosx=tanx, and I worked it out and I thought it was neat. Then I realized thats in chapter 2 of a class I already took. Granted Calculus actually smooths these issues out with more applications you have to use, but I still have times where I have to check the double angle formulas etc.
Huh? To figure out why, you'd need to define them first. What were the definitions you used to derive them?
As a kid, using SohCahToa I basically did sin/cos = (o/h)/(a/h) = o/a = tan. But that's not really a proof because it assumes SohCahToa, and I didn't know what SohCahToa was defined by. (I also used it to remember sin^2+cos^2 = (o/h)^2 + (a/h)^2 = (o^2 + a^2) / h^2 = h^2/h^2 = 1)
I know why Sinx/Cosx=Tanx, and most identities can be derived from them. All I was saying is that I didn't touch on them enough. All I have to do is do practice problems so I no longer need to look at the book. It is nothing serious.
This is going nowhere. All i'm getting is aggravated, because i'm making some examples and you either dismiss them without much thought or you say that me saying something doesn't mean anything when it does (A definition has a proof). It would be better for me to just look at the book and ask questions.
EDIT: Just to clarify, i'm saying that I feel like I don't know enough, and just saying no isn't helping with my supposedly wrong reasoning, so its better to just drop this and I go study more.
This post has been edited by Elnendil: Oct 10 2010, 03:41 AM