It seems that you're using an outdated browser. Some things may not work as they should (or don't work at all).
We suggest you upgrade newer and better browser like: Chrome, Firefox, Internet Explorer or Opera

×
Community
General discussion (archive)Any Hardcore Nerds/Engineers here?(10 posts)(10 posts)
(10 posts)
Pages:
1
This is my favourite topic
Posted December 15, 2011
I've recently started studies in IT and though I think I've done a great job with it generally, there's a certain section of mathematics that baffles me.

I'm talking about 3-dimensional rotation matrix calculations and complex number equations. Does anyone have any good material or know where to find good learning material for these subjects? Though our teacher is, for the most part, very competent there's been a series of circumstances that forced us to rush through these themes and a as a result I basically understand nothing about these.

Here's a good example of a complex number equation that SHOULD be easy (that's what I was told) but I just couldn't find a way to solve it:

2z+(2−3i)(6−5i)=z(1+i)+3

where z is a representation of an unknown complex vector a+bi.

If anyone has ANY helpful advice I'd appreciate it. I have a test on this tomorrow (which I know won't go well) but I'm more interested in actually learning these properly than just barely making it through the test.
Post edited December 15, 2011 by Deus_Ex
Posted December 15, 2011
The answer is going to depend upon the formatting. As written that should be trivial to solve with a bit of algebra.
Posted December 15, 2011
Have you tried using Wolfram Alpha? Of course, only to check your algebra.

Hint:

(2-3i)*(1-5i) = 2 - 3i -10i + 15(i^2) = 2 - 13i -15 = -13-13i = -13*(1+i)
Post edited December 15, 2011 by actiondan
Posted December 15, 2011
That can be written as 2z - (3+28i) = 3+(1+i)z which is (1-i)z - (6+28i) = 0 which means that z = -11 + 17i. That or maybe I didn't understand it.

Also, a comp sci person, in most programming and software engineering jobs you won't really use that "high" level math.
Posted December 15, 2011
It's Technical Mathematics and Calculus right? I already learned this 2 years ago but never fully understand it.

It's hard to find free and complete lesson on the internet. But this might help you:
http://www.purplemath.com/modules/complex.htm
http://www.themathpage.com/alg/complex-numbers.htm
http://www.purplemath.com/modules/complex3.htm
Posted December 15, 2011
avatar
AndrewC: That can be written as 2z - (3+28i) = 3+(1+i)z which is (1-i)z - (6+28i) = 0 which means that z = -11 + 17i. That or maybe I didn't understand it.

Also, a comp sci person, in most programming and software engineering jobs you won't really use that "high" level math.
Ah. I got the same result now after looking this over and giving it another try, thanks!

I still need to tackle those rotation matrix...es? Matri? What's the plural for those darn things?
Post edited December 15, 2011 by Deus_Ex
Posted December 15, 2011
avatar
Deus_Ex: I still need to tackle those rotation matrix...es? Matri? What's the plural for those darn things?
Matrices :) If you want you can PM me them and I'll try and look over them.
Posted December 15, 2011
avatar
AndrewC: Matrices :) If you want you can PM me them and I'll try and look over them.
It's not a particular matrix but the fact that we didn't have time to learn the theory behind them but I'm still interested in actually learning the theory and how/why they are used and where
Posted December 15, 2011
avatar
AndrewC: Matrices :) If you want you can PM me them and I'll try and look over them.
avatar
Deus_Ex: It's not a particular matrix but the fact that we didn't have time to learn the theory behind them but I'm still interested in actually learning the theory and how/why they are used and where
Well, Khan Academy is really good when it comes to most maths things (and from what I understand even other fields) so it's worth checking it out.
Posted December 15, 2011
avatar
Deus_Ex: I've recently started studies in IT and though I think I've done a great job with it generally, there's a certain section of mathematics that baffles me.

I'm talking about 3-dimensional rotation matrix calculations and complex number equations. Does anyone have any good material or know where to find good learning material for these subjects? Though our teacher is, for the most part, very competent there's been a series of circumstances that forced us to rush through these themes and a as a result I basically understand nothing about these.

Here's a good example of a complex number equation that SHOULD be easy (that's what I was told) but I just couldn't find a way to solve it:

2z+(2−3i)(6−5i)=z(1+i)+3

where z is a representation of an unknown complex vector a+bi.

If anyone has ANY helpful advice I'd appreciate it. I have a test on this tomorrow (which I know won't go well) but I'm more interested in actually learning these properly than just barely making it through the test.
Concerning this equation: As you mentioned, just write z = a + bi, multiply everything out (using i^2 = -1), and you will get two equations: One for the real part, one for the imaginary part. In this case, both are linear, therefore easy to solve.
About rotational matrices: I could probably name some standard textbooks that deal with the theory, but those would be mathematics textbook, and if I understood you correctly, you are more interested in how the calculations work and applications for them, so there might be better alternatives.
Though the orthogonal and unitary groups (plus variations and refinements) are very interesting, of course ;)

Maybe not exactly legal, but in my opinion alright for personal study: library.nu
They have a shitload of academic literature; however, it appears to be impossible to register at the moment.
Pages:
1
This is my favourite topic
Community
General discussion (archive)Any Hardcore Nerds/Engineers here?(10 posts)(10 posts)
(10 posts)