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[Zonk]

The day 17 im having MATH exams...Toadyone,since you are some sort of math professor...have you got any tips?

By the way,im also happy about the developing of Slaves to Armok..can't wait to be able to use the editors :-)

I have also noticed that there is bone Tissue but not marrow...i want to be able to lick the marrow of the bones of my enemies!

[spelguru]

And my friends think that I am weird...

[Toady One]

He he he.  Marrow is important for effect, isn't it...  I'll have to think about how best to layer it.  For now you'll have to be content with cracking open a creature's spine and sucking the nerve tissue out.

For math exams, just make sure you've studied and understand the material, Relax, get lots of sleep, and remember that most math test questions are fairly straightforward once you've sat back and thought about how to do them.  What does the test cover?

[spelguru]

In math, I got the best grade of all the students in my group. That was the next best grade you could get.

[Demon]

I think we're just about all math nerds...  I'm competing in a national contest (one from each state, I'm PA champ) on the 24th...  If I win that I have to go to another one...    :roll:

Luckly, its not even the kind of stuff that Tarn considers "math" anymore, so its super easy...

If theres a fairly quick way to explain, would you mind telling me what the heck differential equations are??

[Toady One]

Have you seen any calculus?  If Yes, skip to "Yes".

No:  Consider a function.  In particular, look at its graph.  At every point x, the graph has a "slope".  Call it f'(x).  f' is a new function (the derivative).  You can continue this process (draw the graph of f', and then take its derivative).  Then consider f and all of its derivatives.  For instance, if your function is f(x) = 2x, then the graph is a straight line with slope 2.  So f'(x)=2 everywhere (the slope of the graph is 2).  The graph of f'(x)=2 is a horizontal line at height 2, so at every point, the slope is zero.  So f''(x) (the second derivative of f) is zero.

Yes:  A differential equation is an equation satisfied by a function and its derivatives.  Like, f' = f.  If f = e^x, then f' = e^x, so f satisfies this equation.  Any function f = Ae^x satisfies this equation, where A is a constant.

The function in the "No" paragraph satifies the differential equation f(x)=xf'(x), for instance.  It also satifies f(x)+73f''(x)=xf'(x) (because f''(x)=0).  Differential equations generally have an infinite number of solutions.  You can put constraints on them.  For example, take f(x)=xf'(x).  Our original function f(x)=2x satisfies this, but so does f(x)=Cx, where C is any constant.  But if we specify some constraint, like f'(0)=2, then only C=2 works.

[Demon]

I'm pretty sure I follow that...  So with your example of 2x, you take the derivative of 2x which is 2 then the derivative of 2 which is 0 and the answer is 2 and an infinite occurance of 0 (since f'(x)=0 makes x=0 and you can continue to plug in 0 to get 0 again)?

[Toady One]

I don't quite follow you...  "the answer is 2"?  The answer to what?

Basically differential equations are like old-school 8th grade algebra problems.  Back then, you might be asked the following:

Question: 3x + 5 = 4.  What is x?
Answer: x = -1/3.

For differential equations, you might be asked:

Question: f(x) - x f'(x) = 0.  What f work?
Answer: f(x)=Cx, for any constant C.

Differential equations can be arbitrarily nasty...  just put in more and more derivatives in weirder combinations.  Like, I don't know...

Question: sin(f(x))+f''(x)f'(x)=0.  What f work?
Answer: NFC.  But it's a differential equation.

But to get at differential equations, you need to see some calculus...  to even read them you need to know what a derivative is, which is what I kinda tried to explain.  Hopefully I'll get better at it, since I'm teaching calculus this summer starting next week.  We'll be doing derivatives in July.

[Zonk]

what it covers?honestly,i don't known really..it's about the third year of comprensive school(since im 13 years old)...by the way im also very good at math and geometry but i don't get very good grades because the prof says that im not good at writing "in order"

[ThreeToe]

f(x)=f**k you

[spelguru]

Time times Money   T*M
Time is Money      M*M
                  M2
Girls cost money   M2=G
Money is greed
Greed is Evil      E2=G
Therefore, girls are the root of all evil!!!

I lost the real calculation of this one but I think I got it right.

And TT, don´t curse you m*****f****r!!!

[Demon]

You messed it up real bad...

First, we state that girls require time and money.

Girls=Time*Money

Then we show that time equals money.

Time=Money

Therefore:

Girls=Money^2

Now we show money is the root of all evil

Money=Evil^.5

Then it becomes obvious...

Girls=(Evil^.5)^2

That girls are evil

Girls=Evil

Couldnt figure out a god way to show a sqr. rt. so I used the equavalent ^.5

[Toady One]

I guess people normally type a square root as
sqrt(number).

However, there's something to point out with the above calculation:

Although it is true that

Money = sqrt(Evil),

we all know that Evil is negative.  We can't take the square root of a negative number unless we allow imaginary numbers.  This means that money is imaginary.  Since

Time = Money

Time is also imaginary.  Therefore girls require only imaginary money and imaginary time.  Note that as long as we allow imaginary numbers (which we must for the calculations to make sense),

Girls = Evil

tells us that Girls are real and negative, as long as you know that Evil is negative.  This harkens back to Eve screwing it up for all of us back in the Garden, if that's your thing.  Yeah.

If, on the other hand, we assume Evil is positive, then Money, Girls, and Time are all real and positive, and vice versa.  Therefore, one who thinks Money, Girls, and Time are positive must also consider Evil positive.  We conclude that rich swingers suck.

[Ashelus]

heh.. I'm not a swinger, but 'hi there toady1' from Aris

[Toady One]

Not a swinger, Aris?  Alan and I know better than that.  We have so many stories we could tell...  but no.  I'll hold back.