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05 May 2008 @ 10:32 pm
I have an assignment due where I have to intergrate sin(x)/((1 + x^2)^2) by substuting u = 1/(1 + x^2) and I have no idea how to do it? anyone got any ideas.

11 March 2008 @ 04:14 pm
if f(x) = 1/(x+1), prove that f^2(x) = (x+1)/(x+2).

Hence find an expression for f^3(x)

I really didn't get it, so... if there's anyone out there that could explain it, please do.

Thank you.

13 September 2007 @ 05:48 pm
This is such a stupid question but I just wanna make sure-

10(n-1)²
=
10n²-20n+100

Haha, is that right??

10 August 2007 @ 11:42 pm
Does anyone one know the rules for combing Differential Equations?

Combining

(2)
\frac{dj}{dx} = -C'\frac{dV}{dt} ;

and

(3)
\frac{dV}{dx}=-L'\frac{dj}{dt} ;

I need to get:

L'C'\frac{d^{2}V}{dt^{2}} = \frac{d^{2}V}{dx^{2}} ;

L' and C' are conductance and capacitance per unit length, and d is intended to represent lower case delta.

The problem concerns transmission lines.

09 July 2007 @ 11:36 pm

06 February 2007 @ 05:51 pm
Loscha's great calculator sell off continues. Selling my TI-89 Titanium graphing calculator. In excellent condition.

The most powerful calculator TI make that will fit in your pocket!
It should cost $20au to post internationally. 01 February 2007 @ 05:50 pm What calculators do you own and use? I have (and use) Texas Instruments: TI-84+, TI-89 Titanium, TI-30X IIB (a normal scientific, I have the white/silvery one, but, would love to get a purple/green/blue one, too) and a TI-80 which I got for$5 at a hock shop because it was cute and twee and baby sized.
Casio:
FX-100d quite a rare one. I have 2. It has hex, milli micro nano pico kilo mega symbols on some buttons (very bloody useful for electronics engineering)

Slide Rules:
Three, various kinds. Favourite is a Hemmi (Earnest) my then best friend got me from an op shop she worked at (with it's manual).

Computer:
A really old version of Derive (dos), copied from the computers at my high school back in 1991.
I'm starting to get into YACAS, which I am finding useful.
I've used dodgies of Matlab and Mathematica, but, I'm not good enough at Math to really get maximum value from them.

16 January 2007 @ 11:45 pm

OK, they're not much, but, I thought I'd make some ditzy banners for people to put on their userinfo if they felt compelled to do so. They are made with TI calculator fonts.

16 January 2007 @ 10:59 pm
Poll #907774 How Do You?

What tool do you primarily use to do your math stuff?

Scientific Calculator
0(0.0%)
Graphing Calculator
1(11.1%)
0(0.0%)
Open Source Math Package (YACAS, etc)
0(0.0%)
Matlab, Mathematica, Maple, Derive
0(0.0%)
Pen and Paper
2(22.2%)
0(0.0%)
0(0.0%)
0(0.0%)

Expansion of Q1

I Do Math

Because of My Course (Tertiary, Tafe, University)
1(11.1%)
Because I like It
1(11.1%)
For My Job
0(0.0%)
I need to (for values of need approaching psychological compulsion)
0(0.0%)
I'm a Secondary School Student
0(0.0%)
0(0.0%)

Expansion of Q3

I have the following qualifications

Tertiary Degree (math related)
1(12.5%)
Incompleted Tertiary
1(12.5%)
Completed Secondary School
4(50.0%)
It's my hobby, I just tinker
1(12.5%)
I'm a computer programmer
0(0.0%)

Helping others

I'm here to help others
1(11.1%)
I'm here to get help
1(11.1%)
A bit of both
4(44.4%)
Here to see how this thing pans out
2(22.2%)
I'm here cause I want to stalk other memers of this group
1(11.1%)

16 January 2007 @ 05:12 pm
Hi all, my name is .
I like mathematics.
I'm not extremely good at it, I don't have a degree, but, I enjoy it.
I enjoy helping other people with what I can.

This is a community for people to help others with (probably simple) math problems.

Not everyone knows how to use a normal calculator to work out what 17.25% discount on \$35.50 is.

Hopefully, We can help.

I personally am a Wikipedian, and a Texas Instruments graphing calculator user, and somewhat of a collector of old calculators.
I bet I could add up the change in your purse very fast.