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/sci/ - Science & Math

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1274923 No.1274923 [Reply] [Original]

Alright /sci/ I'm currently a calcfag but at my school the Geometry H teacher was the worst honors teacher by far. I still managed to get double A's but when we were doing trig I never understood WHY you have to use the trigonometric ratios.

I remember asking her, well why cant you just use a constant, multiply both parts by it and then set up a proportion.

She was like, "well you have to use SOHCAHTOA or law of sines/cosines"

I know that you whore but WHY

I'm fully aware of sohcahtoa and the law of sines and the law of cosines...

but if the angle measure directly affects the side length and vice versa, then why can't you just set up a simple proportion (maybe multiply both sides by a constant)?

I know the law of sines is a proportion but I still don't understand why the trigonometric operations are needed at all.

Can someone please explain to me why we just cant set up proportions?

I don't want to ask my Calc teacher and sound like a fucking retard...

It has been bugging me for a while now.

>> No.1274946

don't have a clue what you're on about. can you illustrate it a little more clearly?

>> No.1274943

KAIBA-BOY!

>> No.1274953

The proportions are SOHCAHTOA
Sin is the proportion of Opposite to Hypotenuse at a a certain angle

>> No.1274999

>>1274953
oh wow this makes sense

>> No.1275022

>>1274946
Why do you have to use sine, cosine, and tangent or the law of cosines/law of sines to solve for triangles.

Why can't you just multiply both sides by a certain constant and then set up a proportion if the sides/angles of a triangle are directly affected by each other.

>> No.1275052

>>1275022
But the values of trigonometric function are constants.

>> No.1275070
File: 51 KB, 732x575, UnitCircle.gif [View same] [iqdb] [saucenao] [google]
1275070

Constants. You mean like these.

>> No.1275081

>>1274923

You're a stupid shit for not recognizing a proportion when it's staring you in the face, and the teacher should have flunked you but she's a stupid shit too.

S=O/H
C=A/H
T=O/A

>> No.1275315
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1275315

>>1275070
>My face when I completely forgot about unit circles from pre calc
Thank you very much anon, this is my mistake

>> No.1275321
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1275321

>>1275081
sorry bro no....

my point

------------------

your head

>> No.1275322

I don't get people who do trig without the unit circle. It's like doing physics just by memorizing formulas and not understanding what's going on.

>> No.1275330
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1275330

>>1275081

>> No.1275331
File: 15 KB, 300x208, unitcircle.png [View same] [iqdb] [saucenao] [google]
1275331

I also find this handy for making your own trig identities using the pythagorean theorem.

>> No.1275362

>>1274923

Not everyone knows calc coming into trig broski.

>> No.1275368

>>1275070
>>1275322
>>1275331
Yeah, at my school we do Geometry and trig together but don't learn the unit circle until two years later...

fucking stupid I know, I guess this is why it never clicked

>> No.1275379

>>1275362
what?

>> No.1275421

>>1275315
>forgot
This is what's wrong with education in the US

>> No.1275438
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1275438

>>1275421
ouch

>> No.1275442

>>1275421
rofl and thats what's wrong with education in europe
>>1275438

>> No.1275455

>>1275438
I'd rather have the world's best-educated population than the world's best schools.

>> No.1275468

>>1274923
I'm confused what you're even saying.
Use a constant.
Multiply both parts by it.
Set up a proportion.

Because it's proportional to two things, not one...
What you're saying is like solving
z = xy like this
z = ax where a is a constant.
Yay we're done!
Now I change y.
Now I use a new constant.
It's the same goddamn thing. Changing a constant all the time and using a variable are the same. That is, unless you start doing things to it for which its variable nature is significant. That, however, isn't necessary until calculus.

side-note: I may have done this at one age or something similar to it. Only a few math teachers actually understand it.

>> No.1275471

>>1275468
In that last sentence, by it I mean math, not this.

>> No.1275473

>>1275455
rofl what ever you say bro

>> No.1275479

>>1275438

What good is those schools, if no Americans attend to them?

>> No.1275491

>>1275468
No its cool bro... I understand now, I was just forgetting about the unit circle

>> No.1275498
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1275498

>>1275479
lol
0/10

>> No.1275501

>>1275455

you have neither, though.

http://en.wikipedia.org/wiki/IQ_and_the_Wealth_of_Nations

>> No.1275506

>>1275479
Statistics say otherwise, but whatever lets you Europeans keep that "lolol we are soooo muuch smrter than Americans" complex