Apologise, I forgot to change Denaya Lesa’ address at leave comment before submitting the above reply comment. She is is my daughter. And we use the same computer for uploading comments.

Bye bye…

Afasmt/Rohedi

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And of course this can’t be something new.

And surprise surprise if you plugin to the original eq. we get and if substitute to the latter we get . So? Nothing important there, both of them are undefined and we can’t compare the two. ]]>

Your so called new formula for tangent as I said earlier is nothing but a simple substitution from the second eq. So there is nothing special about your equation.

Or do you want something like this?

. ]]>

Sorry, I mean at the above phrase is the following sentence

But, before we continue this discussion…

]]>Oh suprise Sir,

So many thanks for your great efforts in searching the related references for our discussion here. I believe this will be useful not only for me, but also for my visitors.

But, before we continue this continue, I need your help again to search the book references and/or journals that presented the formula of tangent function

tan(t)=sin(2t)/[1+cos(2t)],

but sorry not in the form

tan(t/2)=sin(t)/[1+cos(t)]

as appear at your last post.

This is very important to prove whether my claim that tan(t)=sin(2t)/[1+cos(2t)] is the new formula for the tangent function that only can be created by using SMT.

Okay, I am still waiting you here. Thx.

]]>You think that which is incorrect and I suspect that this misunderstand is rooted from the practice of highschool teacher teach this concept in Indonesia.

Let me stressed again has no meaning, but we can talk about $\latex \lim_{x\to (\pi/2)^+}\tan x$ and $\lim_{x\to (\pi/2)} \tan x$ ]]>

So basically NaN is a symbol when a certain operation can’t be computed (my word). Mathematically is always undefined and so is .

Again here some cases that can produce NaN according to wikipedia:

The following practices may cause NaNs:

* All mathematical operations with a NaN as at least one operand

* The divisions 0/0, ∞/∞, ∞/-∞, -∞/∞, and -∞/-∞

* The multiplications 0×∞ and 0×-∞

* The additions ∞ + (-∞), (-∞) + ∞ and equivalent subtractions.

* Applying a function to arguments outside its domain, including taking the square root of a negative number, taking the logarithm of a negative number, taking the tangent of an odd multiple of 90 degrees (or π/2 radians), or taking the inverse sine or cosine of a number which is less than -1 or greater than +1.

So in particular (the second case) and (the last case) all produce NaN.

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