Aargh why don't they teach math I could use in school

Pretender

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Mar 14, 2000
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I'm only in Junior level HS math, but I'm in the advanced class. Anyway, we finally got to learning polar coordinates (using (r, Ø) instead of (x,y), btw, Ø = theta for the rest of this post).
Seems good and all..... rcosØ = x, rsinØ = y. No problemo.

Except one thing....how does this work in 3 dimensions? Unless there's some sort of mystical trigonometric function which doesn't appear on any calculator, I'm guessing you need a second or third angle to do this in a 3 dimensional plane, and it's all just frying my brain.



I'm not trying to be an overachiever, but it's hard to try to do 3d programming stuff (non-school related) without knowing this crap.


 

Xede

Senior member
Oct 15, 1999
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In rectangular coordinates you need 3 parameters to describe a point in 3D (x,y,z). Same goes for polar. You can either have cylindrical coords (r,theta, and height), or spherical coordinates (r,theta,phi), where the new angle is like an angle of elevation.
 

hendon

Senior member
Oct 9, 2000
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The third dimension is the z-axis, just like in the Cartesian coordinates... It's called the cylindrical coordinates system...

 

BA

Diamond Member
Dec 3, 1999
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just wait until you get to start doing calc in polar coordinates...
 

pidge

Banned
Oct 10, 1999
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No, wait until Chemistry class. Especially if you go to college and have to take Organic Chemistry.
 

jhu

Lifer
Oct 10, 1999
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ha! organic chemistry was a joke. wait until you do biochemistry in med school
 

pidge

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Oct 10, 1999
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<< ha! organic chemistry was a joke. wait until you do biochemistry in med school >>



Organic Chemistry made me change my major. I have much respect for you jhu.

BTW, I was just stating that OCHEM is just a class that I could never see myself applying it to the real world in my situation. However, I do use math alot.
 

Mucman

Diamond Member
Oct 10, 1999
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um, a mole is a very useful convertion!

I you had 1mole of H how many grams would that way? 1, isn't that easy?

It's better than writing 6.whatever x 10^whatever all the time (sorry I forgot the exact amount of a mole, my chem book is in another room). The mole makes chem equations so easy when you are dealing with simple numbers instead of enormous powers!

IOW, don't under-estimate the power of the mole!
 

mAdD INDIAN

Diamond Member
Oct 11, 1999
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Chemistry is sooo bullshit!! How can they prove to you how the electrons move around the atoms??

And they lie to you all through your years of high school.

In Gr.9 Science we learnt that atoms are the smallest type of matter
In Gr.8 We learnt that protons/neutrons are smaller
In Gr.11 Chem we learnt that electrons orbit the nucleas
In OAC Chem you'll learn that not all electrons orbit the nucleas...some stay put..and some move..
In University Chem...you'll learn that Quarks are the smallest type of matter..

it's all lies...LIES..i tell you!!
 

Napalm381

Platinum Member
Oct 10, 1999
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1 mole is 6.02*10^23 particles.

Moles are a far more useful unit of measure for chemical matters than grams and such. Stoichometry is a no brainer with moles, with mass units it would be a headache.
 

jhu

Lifer
Oct 10, 1999
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i've noticed that in college physics majors look down upon chemistry majors and chemistry majors look down upon biology majors.
 

Mday

Lifer
Oct 14, 1999
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there are 2 &quot;polar&quot; correspondencies in 3d in so far as the &quot;geometry&quot; goes

one is cylindrical coordinates, which means it's just the 2d polar extended along it's central axis, defined by an angle, a radius (distance) and a z coordinate.

the second is called spherical. 2 angles and a radius.

wait until you have to deal with the calculus in these new coordinate systems =) it's fun stuff...

actually, i don't recommend spherical unless you have a firm basis in vector calculus... or basic vector arithmetic
 

Mday

Lifer
Oct 14, 1999
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at least you don't know what a hyperbolic parabaloid is... and worse of all, i know what it looks like and CAN DRAW ONE!... and i don't mean just drawing something that looks like a saddle either...
 

Mday

Lifer
Oct 14, 1999
18,647
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pretender, life gets sad when you have to represent y = x^2, well complex composite functions anyway... in polar =( nasty sh!t
 

Pretender

Banned
Mar 14, 2000
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Ok mday is scaring me.

Is there some sort of formula or something I can use or will I have to try to interpret what Mday said, minus the rants about how hyperbolic parabaloids are evil.
 

vi edit

Elite Member
Super Moderator
Oct 28, 1999
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&quot;Chemistry is sooo bullshit!! How can they prove to you how the electrons move around the atoms??&quot;

Ahh, but if you stick through chemistry and go into pharmacy, I bet you would stop complaining when the 60k+ a year salary starts rolling in ;)

Oh, and for useless math, I throw my vote in for imaginary numbers....and logs :)