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/sci/ - Science & Math


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File: 30 KB, 1037x429, sin.png [View same] [iqdb] [saucenao] [google]
6803429 No.6803429 [Reply] [Original]

>mfw I realised that cosine is actually sine with 90 degrees phase shift

>> No.6803442

Is that really your face? You don't look like a human at all.

>> No.6803480
File: 218 KB, 628x317, sin cos.gif [View same] [iqdb] [saucenao] [google]
6803480

>>6803429
>not seeing that sin and cos are obviously just taken from another angle (90° apart)
also sin(x+π)=-sin(x)
and cos(x+π)=-cos(x) obviously

>> No.6803486
File: 42 KB, 768x421, 1365535596908.png [View same] [iqdb] [saucenao] [google]
6803486

>>6803442
le sinus faec

>> No.6804286

The cofunction identities tell you this explicitly.

>> No.6804309

Tfw the slope of the line on a sine graph can be expressed by the value of the cosine so long that the inside function is theta alone

>> No.6804318
File: 12 KB, 366x279, circle-unit-304560.gif [View same] [iqdb] [saucenao] [google]
6804318

have you never heard of a unit circle?

>> No.6804333

>>6803486
This is more perfect than the person writing it could have hoped for. One of the biggest problems the Mississippi faces is from a distinct lack of twists and turns.

>> No.6804684
File: 69 KB, 645x773, 192837465.jpg [View same] [iqdb] [saucenao] [google]
6804684

>tfw you realize <span class="math">\frac{1}{x^{2}+1}[/spoiler] is just a single, streched out period of <span class="math">cos^{2}\!(x)[/spoiler]
>tfw an infinite flood of trigonometric identities become obvious and apparent to you
>tfw you dream of being a triangle

>> No.6804719
File: 253 KB, 700x700, jvzRYnC.gif [View same] [iqdb] [saucenao] [google]
6804719

>>6803480
This image a shit.

>> No.6804749

>tfw euler's formula

>> No.6804760

>>6804684
So cos^2(x/a) converges to 1/(x^2+1) when a approaches infinity?

Is the proof trivial?

>> No.6804806

>>6804760
cos^2(x/a) converges to 1 as a approaches infinity
1/(x^2+1) converges to 0 at infinite and negative infinity
the tangent function has vertical asymptotes at the ends of its period, so it shrinks 1/(x^2+1) down to its period, making pi/2 and -pi/2 0. this ends up being cos^2(x). it's relatively easy to prove too. just thought it was a neat relation and it helped me make the connection between tan^-1(x) and 1/(x^2+1), and other various identities.
i'll get some pics in a minute