Survey posted 2003-06-06 23:32 by Henrik.

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No because:
-I don't have that calculator
-I don't know anything about 3D graphing

What about 3D Graph for the 83+? Can you make it on there? Someone? Anyone?

Yes, there is a FLASH application that can be used on the TI-83 Plus. It works pretty well and is very fast, but it has crashed my calc a few times :-)

Anyway, see URL above, or:
http://www.detachedsolutions.com/graph3/

He knows about Graph^3, I think he was asking if it were possible to make the same graph on the TI-83+ with Graph^3, which I assume is possible, if the equations were the same, and you got the same perspective on the graph...

Thanks, no_one, you're right!
Yes I know of Graph3D and have it on my calc. Just wondering what the equation is.

Me too... every time somebody comes up with one that works, somebody else says that it doesn't... LOL

Maybe if I keep on looking down, somebody will have gotten it :)

Um...just how did you get the Subject line to be blank?

Great! I'm glad somebody noticed!!!!

Hint:  

It shows up as a "?" on my other browser, for some reason.

OMG! A DS application that ACTUALLY CRASHES???? *PANIC*

What exactly did you do to get it to crash?

Not on my 82 strangely.

But it seems to be a 3D sinc() graph.

(sinc(x) = sin(x) / x). I only found this out about one week ago. Such a strange coincidence that the question is asked now...

May I ask what sinc(x) is?

Or, even better, can you convert the equation to find z in terms of x and y?

BL Alien

change x to sqrt(x^2+y^2)
the range appears to be -3*pi to 3*pi in both x and y

or in reply to the comment that will be just under this for a short time.....

sinc((x^2+y^2)^.5)

It must be a good half year sinse I did any 'maths' other than the useful variety.

or even....
sinc(|x+y|)

Did you do that change in your head? Because those two equations are not equivalent...You CANNOT idstribute a square root to sums!

|x| is the modulus / magnitude of x.

for example using complex....
a+jb can be shown as re^o (r times e power theta.)
where
r = |a+jb| = (a^2 + b^2)^(1/2)
o (theta) = arctan(b/a)

or a more basic one
|-x| = x

so |x+y| means the magnitude of the two. Treated just like complex values. I was assuming that people wouldn't just add the two independent values together then remove any minus.

....Engineers spend most of there time in an imaginary world....

Right then sinc was explain in my post for 2D draw it and you will see what I mean
[sin(x)]/[x]
[] are used just to show two seperate parts of the equation.

as to 3D well then,
try

sinc(x) + sinc(y)
sinc(x) + cosc(y)
(assuming cosc follows same rule as sinc)
sinc(x+y)
sinc(x^2+y^2)
sinc(x/2+y/2)

or various combos. Can't test it myself I don't have a 3D graphing calc, or Matlab. Last ones are most likely to be correct.

Tell me your results could you old bean.

I don't think you ever answered his question: WHAT IS SINC (and cosc now...)????

Read the first line.
And, if that taxes you too much then skip reading that and read the first post of mine.
And, if you are still, for some unnecessary reason, unable to do that, then I shall say it in very, and I shall emphasise the word <em>very</em>, capital letters.

SINC (X) = ( SIN (X) / X )

see I even added some spaces to make it REALLY CLEAR.
Now have I answered his question?

As to what cosine is, it is about half pi radians ahead of sine.

The equation is, I believe,

apple = sinc [(orange^2 + banana^2)^(e^-693147181n)]
where the suffix 'n' means 'nano'.
And, Pie is very tastey and is exactly equal to 9,
and a square Pie is exactly equal to 81.
(
9 = 8.539734233
81 = 72.92706059
10 = 2
bed = calling me
)


(Sorry about the tags earlier but they had to be used)

Get some sleep then! You're posting nonsense!

No. All of that is perfectly logical.

Remembering that 3 is a pretty good approximation for pi, and it will do for a rough approximation for e.

I was referring to paragraph 7 and on :p

p7 - is that the equation bit?
Because it isn't nonsense, not really. Apple is just a label and so is x, etc.
The rounding certain values to different values is more then legit. (and 10 = infinity = 2, but that is a long story dating back to school days and graphing calcs.)

actually 1=0=infinity
it is the truth

Exactly, and 1 = 2 as well. Isn't maths a fun thing to play with.

Actually, theoretically speaking, if you use the old fashioned way of thinking, and declare 1=2, you could prove this by stating that o=1, n=1, and e=2, or any combination of three numbers, when multiplied, equals 2. that would make the statement 1=2, or one=2 correct. Also, the same can be flipped, and said the other way. All you have to do is make sure that the variables you assign for the letters of the phoenetic spelling of the number multiply out to the value on the other side of the equation.

Now, if we think further into the topic, we can theoretically disprove that statements can be false. All we would have to do is break up all the numbers into letters, assign variables to the numbers so that the equation is balanced. Here is an example.

Dog = Cat

Well, if we say the following,

D=t
g=a
o=C

Then the statement Dog = Cat is true and correct. This can also apply to nonmatching variable numbers like the following example.

Cat = Mouse

Well, there are more letters in Mouse than there are in Cat, but by using the following table of values, this can be proven correct.

C=1 M=5
a=20 o=2
t=5 u=1
s=100
e=0.1

These values will prove that Cat does indeed equal Mouse.

x = 1, y = 1

x = y
xy = y^2
xy - x^2 = y^2 - x^2
x(y - x) = (y + x)(y - x) ; divide both by (y - x)
x = y + x
1 = 1 + 1
1 = 2

(Obviously there is a slight flaw to the logic, in that if you divide something by zero it ceases to exist, and y - x must always be zero. But it is an ammusing 'proof' anyway.

2 = infinity....
you have a square wave with period 4secs.
to find the Fourier transform you multiply by a value and integrate over infinity. But as the wave only exists for four seconds you only need to integrate between -2 and 2. (so 2 = infinity).

if x = y = 1, then y-x = 0, and you can't divide by 0 :p

Well, technically you CAN divide by 0, but if and only if this is true:

If a/b = c implies c*b = a and c*b = a implies a/b = c, then a = b = c = 0 is a solution.

This is the only time in math where dividing by 0 gives a valid solution.

You can always divide by zero. But that part of the equation just ceases to exist, bit of a shame. even 0 / 0 ceases to exist.

NB 1/x -> infinity
as x -> 0

However the situation 1/0 does not give an answer of infinity, just for those who thought it does.

*amusing (two posts up)

So if 1/x -> infinity where x=0, would y/x -> (infinity + y) if y were any number because 0*infinity = 1?

No No No.
1/x tends to infinity as x tends to zero.
1/x doesn't exist when x is zero.
zero multiplied by infinity is zero not one.
Infinity means everything Infinity + Y therefore is nonsense, Y no longer exists as a seperate entity, it is part of infinity.
Zero is nothing, zero amounts of everything is nothing.

z(in) = z(0)[z(L) + jz(0)tan(Bl)] / [z(0) + jz(L)tan(Bl)]

if z(L) = inf. seperate z(0) disappear.
z(in) = z(0) / j tan(Bl)
j being the imaginary part of the complex number (a+jb)

there are some proofs in integration that show dividing by zero != infinity, but actually is nothing (zero)
1 / infinity is close to zero, but isn't ever going to quite be zero. It is mearly an approximation.

actually you should be able to divide by 0. if any number divided by itself equals 1.. then 0/0 should equal 1.

also.. try 0^0 on your calculator :S

A calculator is told x^0 = 1. so if the power is zero the calc will ignore the x whether it is zero or not.

nothing divided by nothing is still nothing, not one. Zero is better thought of as a quantity not a mathematical number / symbol.

If the universe were to follow all these silly little theories people come up with we would cease to exist.

And, on the funnier side.
I spell words as I pronounce them in my head.
I have just tried spelling zero as thero...
...I have a pen between my teeth. Now that is wierd.

LOL :)

I always thought that 0/0 could be anything, since you can multiply anything by zero and still end up with zero... (If that sounded dumb (which, it probably did), then I meant like 6/3=2 because 2*3=6)

Zero is weird

I've seen that one before :) I stumped a lot of people with it at school LOL

Sometimes my math teacher uses beer and grandma. not the words, but pictures of the objects. A beer can and a grandma.

What does he use the pictures for?
If you drink to much of this you will look like this when you are 40.

Or, if you spend money on this now, when you are one of these you won't have any to spend on your heating bills. Because there won't be a pention. And, I am not in the slightest bit disgust with the way this country is run. Honest.

Or, does...
beer = Dear old Grandmama.