How Do You Prove Trigonometric Identities with Minimal Equations?

[Evangeline101]

That's fine. You just need to be careful, the = is saying something very precise.

what do you mean?

 

[Student100]

what do you mean?

The above line that I posted, you're saying the original expression is equal to 2tan(x), which isn't true. I know it was a typo, just make sure you're careful is all. No sense losing points on a typo. =)

The fixed solution looks fine to me.

 

[Evangeline101]

The above line that I posted, you're saying the original expression is equal to 2tan(x), which isn't true. I know it was a typo, just make sure you're careful is all.

Okay, thanks for the help! :)

 

[Evangeline101]

Sorry for responding to this thread after it has been marked solved.

Ok, I am proving the exact same identity, I looked through the thread and the explanations were very helpful.

I wrote out the answer, and would just like to know if I have written the answer properly:

LS= tan x - 1

 

[epenguin]

Yes I think that's right now.
Hope you see it as simple now, and what you were missing.

One of the handful of formulae constantly useful to remember fluently, difference of two squares - and then difference of two n-th powers.