/sci/ - Science & Math

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somehow you went from <span class="math">\cos^2 + \sin^2[/spoiler] to <span class="math">-\cos^2 + \sin^2[/spoiler]

>>2676063
ah. derp.
so what do I change?

Come on. _:Help me out. I'm no math genius, I major in chinese and economy and wanted to show this to a girl studying math.

>>2676042
Who the fuck uses degrees instead of radians? I'm sorry, but this relationship is over.

>>2676063

no, it's -(cos+sin) not -(cos)+sin

>>2676119
use this sin^2+cos^2=1

>>2676162
Where?

>>2676108
who the hell still knows what degrees are?


and wtf, sqrt is a function defined on R+, mathfag!

>>2676178
-4(-(cos^2(45)+sin^2(45))^1/2)=4(sqrt(1))=4

mathematically that doesn't make much sense.
how can you say i is smaller than something?

>>2676200
you appear to be ignoring a minus sign
>-4(-(cos^2(45)+sin^2(45))^1/2)
>(-(cos^2(45)+sin^2(45))^1/2)
>-(cos^2(45)+sin^2(45))
>-

>>2676211
gotta be joking...

>>2676215
Well, I misread what you did slightly, but still
You can't pull that minus sign out of the square root to cancel the one infront of the 4.

>>2676225
question: are your parentheses correct?
bcz: sqrt(x+y)=(x+y)^1/2
and -sqrt(x+y)=-(x+y)^1/2
but sqrt(-(x+y))=(-(x+y))^1/2

>>2676225

-(cos^2(45)+sin^2(45))^1/2 = -sqrt(cos^2(45)+sin^2(45)), not sqrt(-(cos^2(45)+sin^2(45)))

>>2676238
>>2676241
sorry, I was just reading from the second line on the image. It appears I didn't even get which bit you were calling the error on.

Heavy.
But none of your calcs give OP his desired answer.

Is this even possible?

>>2676419
no, the complex numbers do not form an ordered field, since in any ordered field a square number which is not 0 must be strictly greater than zero.
So the statement "i < ANYTHING" is utter bullshit regardless of what ANYTHING might be.

>>2676437
They do if you assume the axiom of Choice :3

Where does the first line come from?

>>2676468
You can well-order them with AC, but they won't be a field. Nice try though :3

OP here, so, I can't form any mathematic equation to be a little witty?

>>2676515
you can change this equation around slightly, but if she's anything like /sci/, you'll get called out on this
>>2676437

>>2676468
well ordering has nothing to do with this, idiot.

In a well ordered set, every subset has a least member with respect to ordering. The real numbers aren't well ordered, and the possibility of well-ordering the reals is actually used as an argument agains the axiom of choice, since it's complete counterintuitive.

And then of course, a well-ordered set has nothing to do with a field. In fact, a field with a well-ordering can never be an ordered field with that order (trivial to prove. Just use that negative numbers get arbitrarily big in an ordered field (by repeatedly multiplying with anything > 1), so there are always subsets of ordered fields which have no least element with respect to that ordering.)

tl,dr: dumbass.

>>2676534

What about finite fields?

>>2676566
see? Why am I even talking to you about this?
Do you even know the definition of "ordered field"?

If not, please look it up now.

You will see that it IMMIDEATELY follows that any ordered field MUST have characteristic 0 (and as a consequence of course cannot be finite).

>>2676580

The point isn't what I know or don't know, the point is that I found a fundamental flaw in your argument. If you're not adult enough to accept certain facts then gtfo.

>>2676607
>I found a fundamental flaw in your argument
>doesn't even know the definitions I'm using
how the FUCK can you find a flaw in my argument if you don't even understand the words I'm using?
(Like ordered field, for example.)

tl,dr: dumbass.

>>2676526
Well how do I do that?

>>2676621

You're being unnecessarily cruel. Stop it.

The guy is wrong, but you've no right to verbally abuse him. I'm sorry bad shit is happening in your life, but chill the fuck out. I get what you're saying and I agree completely, but fix the fucking attitude.

>>2676718
I admit, this >>2676534
was unnecessarily abusive. However this >>2676580
doesn't even contain name-calling. I even said please, here:
>please look it up now. [the definition of an ordered field]

In the third post I call him a dumbass, since he claims he found a "fundamental flaw in my reasoning", without even knowing the definition of what I'm talking about.

My argument was about ordered fields, he admittedly doesn't know what ordered fields are. Still he insists that he found a "fundamental flaw" in my statement which was about ordered fields, and he doesn't know what that is.

That's a dumbass in my book.

>>2676761
he doesn't know what *those are