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#3401 Re: Maths Teaching Resources » some amazing apps » 2011-01-09 18:12:01
ok bobbym, nice to know you 
keep up the good job of helping people with their math...
#3402 Help Me ! » Permutations, given a set of repeated digits » 2011-01-09 17:31:08
- gAr
- Replies: 15
Suppose there are few digit {n1, n1, n2, n2, n2, n3, n3, n3 ... }, is there a simple way to find the no. of k-digit numbers?
E.g. , integers given are {1, 1, 2, 2, 3, 3, 4, 4, 4, 4}, how many 4-digit numbers can be formed?
Is there a method other than listing it manually 1122, 1123, 1124 ... and then adding the permutation of each of the 4-digit numbers??
At first I thought there must be an easy way, but wasn't able to figure it out.
#3403 Re: Maths Teaching Resources » some amazing apps » 2011-01-09 15:14:51
yes bobbym, i agree... but I believe no one can really keep track of the no. of linux systems used. Download counts won't give the counts of the systems, since in many cases it's installed in multiple systems and shared offline among users.
sage windows port may be availble in the future - http://windows.sagemath.org/
for now, a windows installer has been created. It's mentioned "Technically it is similar to a WUBI install, but automated"... But I haven't tested it -
http://groups.google.com/group/sage-edu/browse_thread/thread/10d4bbf40c6f39ca?fwc=1
and do you still write assembly codes? Which assembler are you most comfortable with? I find fasm to be good...
writing asm codes is really the way to learn computers!
#3404 Re: Maths Teaching Resources » some amazing apps » 2011-01-09 05:43:54
Hi bobbym,
thanks for mentioning the apps...
ya, windows is the standard, though it's sub-standard 
. I too used it as a beginner. The main reason I can think of is that the vendors pre-install windows in most of the systems. I was so used to ctrl+alt+del!
#3405 Maths Teaching Resources » some amazing apps » 2011-01-09 04:59:44
- gAr
- Replies: 17
Below are some of the apps, which would help teachers and students -
sagemath - it's the best among computer algebra systems available for free. I guess only mathematica provides more functions than this, which isn't free.
But I love sage, it's simply great! You can find ebooks teaching you calculus with sage, and documents exploring other areas of math as well.
geogebra - a cool application for exploring and knowing about geometry!
K3Dsurf - An extremely fast 3D surface generator. The fastest I've seen yet.
If you use any other apps, please let us know
#3406 Re: Help Me ! » Helpi with finding the inverse of an exponential function » 2011-01-09 04:09:01
you mean, you want to prove arcsinh(x) = ln[ x + sqrt(x^2 + 1)] ?
it's answered here -
http://answers.yahoo.com/question/index?qid=20080810012626AAupFhq
#3407 Re: Help Me ! » Helpi with finding the inverse of an exponential function » 2011-01-09 01:55:01
You don't need to do much.
the given function is
hence the inverse is , which is