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/sci/ - Science & Math


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4702325 No.4702325 [Reply] [Original]

<div class="math"> e^{i\pi}+1 = 0 </div>

>> No.4702331

>>4702325
do you know at least how to prove it?

>> No.4702330

Oh hello, welcome to mathematics. We all hope you enjoy your stay.

>> No.4702333

<span class="math">e^{-1/\pi}=1/2[/spoiler]

>> No.4702339

>>4702331
do you?

>> No.4702352

>>4702331
>>4702331
quit being such a faggot. Even an engineer could prove it with the maclaurin series.

>> No.4702367
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4702367

>>4702331
e^(i*pi) = -1. Then you add 1 to each side of the equation.

>> No.4702380

The most accepted proof is the Taylor expansion of e^ix

>> No.4702386

>>4702380
>The most common and easiest proof
fix'd

>> No.4702409

>>4702325

e^(theta)i = CiS. Proof complete.

e^(pi)i = cos (pi) +isin(pi)
= -1 + i0
=-1
Thus, e^(pi)i +1 = 0.

>> No.4702410

can someone explain to me why e^(i*x)=cos(x)+i sin(x)

>> No.4702414

>>4702367
>romney
>got this

I guess if you mean making america a third world country then, YES. Romney got it!

>> No.4702427

>>4702410
I bet Euler can. Ask him. it has to do with polar polar form of complex numbers. I dont know exactly how to derive it.

>> No.4702435

>>4702410
see>>4702352

>> No.4702437

>>4702410
Taylor e^ix boy, then compare it to the sin and cos functions.

>> No.4702443

>>4702437
it's called Maclaurin series you stupid fucking engineer

>> No.4702454

Does this constitute a proof?

Let <span class="math">y = \cos(x) + i\sin(x)[/spoiler]
<span class="math">y' = -\sin(x) + i\cos(x) = iy[/spoiler]
<span class="math">y = A e^{ix}[/spoiler]
Plugging in <span class="math">x = 0[/spoiler],
<span class="math">1 = A e^0 = A[/spoiler]
so <span class="math">A = 1[/spoiler] and
<span class="math">\cos(x) + i\sin(x) = e^{ix}[/spoiler]

>> No.4702461

babby's first "deep" result

>> No.4702471

>>4702443

A Maclaurin series IS a Taylor series by definition. It is just a special case of it.

durrrr

>> No.4702487

e to the ix = cos x + isin x cause

e^x = 1+x+(x^2/2)+(x^3/6)+(x^n/n)
so e^ix = 1 + ix -(x^2/2) -i(x^3/6) + (x^4/4) etc.
all reals are cos x, all complexs are isin x

Are there other ways to prove this, though?