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| 24 May 2014 10:38 PM |
| Idk y its so hard to some people |
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| 24 May 2014 10:39 PM |
Wait until you approach Pre-calculus and Calculus.
inb4mods |
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bibbs123
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| 24 May 2014 10:40 PM |
then can you help me with some homework
2cos(2x)-1=0
what is x |
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comiconor
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| 24 May 2014 10:42 PM |
@bibbs
I tried to do it mentally, and I think x = 30. |
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| 24 May 2014 10:46 PM |
I'm sorry but I lied I suck at algebra |
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comiconor
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| 24 May 2014 10:48 PM |
My calculator agrees.
My mental reasoning:
2cos(2x)-1=0 2cos(2x) = 1 cos(2x) = 1/2
Now, I remember from something I was talking about with my freind who is trying to teach himself trigonometry (I taught myself a while ago) that sin(30) = 1/2, and I remember remarking that there is a counterpart for cos, which I am fairly sure is 60. 2x = 60, so x = 30. |
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| 24 May 2014 10:48 PM |
@bibb
what's the "cos" supposed to be? I'm in algebra and I've never seen that |
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| 24 May 2014 10:50 PM |
| Superior, just because I say I'm 11, it doesn't always mean I'm telling the truth. |
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bibbs123
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| 24 May 2014 10:50 PM |
it'd be 15, 115, 195, 345 degrees, aka pi/6, 11pi/6, 13pi/6, 23pi/12
i think i did it mentally just now |
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Blockfied
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| 24 May 2014 10:51 PM |
| Uh I'm pretty sure I took algebra and passed the ECA cos isn't in Algebra 1. |
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comiconor
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| 24 May 2014 10:51 PM |
@Why
it's the trigonometry function cosine.
If we have a right angle triangle, and we know the hypotenuse (c), and one of the two angles (besides the 90 degrees), then if we multiply the length of the hypotenuse by the cosine of the angle, then we get the length of the side connected to the angle like this <, and if we multiply the length of the hypotenuse by the sine of the angle, we get the length of the side opposite the angle. |
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INROAD
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| 24 May 2014 10:51 PM |
| the first assignment easy A. |
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comiconor
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| 24 May 2014 10:52 PM |
@bibbs
I disagree with you.
x = 30 degrees, 390 degrees, etc. |
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| 24 May 2014 10:52 PM |
@Comic
Are you talking about the Pythagoras theorem? |
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comiconor
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| 24 May 2014 10:53 PM |
| Well then I have no idea what you just said since I haven't taken trig yet |
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bibbs123
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| 24 May 2014 10:54 PM |
wait no i just did 2sin(2x)-1=0
pi/6, 5pi/6, 7pi/6, 11pi/6 in radians 30, 150, 210, 330 degrees
mental trig woo |
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bibbs123
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| 24 May 2014 10:56 PM |
| so yeah, you were basically right. you just only got one of the x values |
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bibbs123
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| 24 May 2014 11:01 PM |
| remind me to never do trig this late at night |
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| 24 May 2014 11:06 PM |
All I can say is that I personally loathe quadratics.
We've spent the entire semester focusing on those things, and despite trying time and time again to think of some use for them(any use), even from a high-level programming standpoint, I have failed.
I've never had to use quadratics to create a parabola in programming. The idea of it is preposterous when a loop can do the same thing with a simple subtraction problem on a 2-axis plane. |
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bibbs123
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| 24 May 2014 11:23 PM |
| quadratics come up a lot in science so |
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