DreamTheaterForums.org Dream Theater Fan Site
General => General Discussion => Topic started by: Sigz on May 05, 2011, 06:01:07 AM
-
Studying for my maths exam, this was in the solution to the fourier series expansion question from last year's exam:
(https://i.imgur.com/sTU8a.png)
I can do everything else in the problem, but I don't understand how they from the 2nd step to the 3rd. Halp?
edit: OH GOD I WROTE MATHS NOT MATH AGGGGHHHHJDFJKFJASDKFJHSFKJ
-
Looks like a trig identity...let me check...
-
Yep, product to sum formula:
cos(u)sin(v) = (1/2)[sin(u + v) - sin(u - v)]
Which explains why the 2 on the outside of the integration went away as well.
Edit: Wrote the wrong identity
-
Ah many thanks, I figured it was an identity I didn't know/remember. :heart :heart :heart
-
Of course, baby. <3
But if you use the word "maths" again I'm gonna castrate you.
-
hawt :-*
-
OH GOD I WROTE MATHS NOT MATH AGGGGHHHHJDFJKFJASDKFJHSFKJ
Then you wrote it correctly ;)
-
I hate trig identities with a burning passion...
-
I got to the part with the "a" and I just gave up from there.
-
I hate math... :\
-
I hate Trig identities. Pain in my balls.
-
Why the hate? Because there are like 2,000 of them? :lol
-
Why the hate? Because there are like 2,000 of them? :lol
Exactly.
-
Pretty much. They're just a pain in the balls.
-
I hear ya....taking a calc 3 test where you have to remember those rare identities was not fun. If I was a calc teacher, I'd let my students use a trig cheat sheet.
-
I used a trig cheat sheet. My teacher was cool. I also don't think many were rare.
Normal ones, inverse, half angle, double angle, adding, subtracting, multiplying...
-
I hated those identities, until I learned about ei*Phi stuff. After which all those identities were no longer needed.
rumborak
-
When I took calc, there were some that were used once over the course of all three calc classes, so there were a lot that were rarely used
-
I'm not looking forward to calc just because of these things. I adore algebra. The shit we are doing now, there is a good 3-4:1 ratio of variables to real numbers. That is when you know everything is right in the math world.
-
Calc is a whole new level. One way to think about it is that algebra is a very static system of math (still very useful of course)...but calculus takes algebra and extends it to have so many more applications (and with a lot more operations and rules).
-
I hated those identities, until I learned about ei*Phi stuff. After which all those identities were no longer needed.
rumborak
What topic do you learn that concept in?
-
I just like variables. :D
The problems take forever, and you feel like Jesus once you're done.
-
I remember sitting in my calc 2 class one morning and the following thought hitting me: "When I was in algebra, I thought that once I took calculus, I know everything. I would be able to command numbers to bow down to me just be giving them a stern look. Now that I understand what my professor has just put on the board, I realize that although I aced my first semester of calc and am midway through my second, I know absolutely nothing."
-
Just to say that when we did e^(i*pi) etc in uni (school it was its own module of the four-unit course) we did it in the first weeks of Differential Calculus. Also that it is definitely maths.
-
Yeah, but rumborak was talking about e^(i*phi). Phi is something different than Pi. I know the whole e^(ix) = (cosx + i*sinx) from differential equations.
-
Trig identities weren't too bad, but I missed the day where we went over the double-angle and half-angle identities, so I was well-fucked and far from home for a while.
The stuff we're doing in my pre-calc class right now is incredibly easy. Graphing rational functions is absolute cake compared to some of the shit we were put through in the first semester.
-
I love that shit. You mean piecewise functions and shit?
-
The last two posts are funny to read if you read them in the avatars' voices. :lol
Are you both going onto calc at some point?
-
I'm not sure. I'm going into music education, so I'm not sure if I'll need to move onto Calc or not for my general education stuff. If I don't have to, I probably won't. My schedule's going to be slammed as it is.
-
Yeah. I'm taking calc next year. I'm probably looking forward to that class more than any other.
-
Yeah, but rumborak was talking about e^(i*phi). Phi is something different than Pi. I know the whole e^(ix) = (cosx + i*sinx) from differential equations.
Never heard of that. What is it?
-
Yeah, but rumborak was talking about e^(i*phi). Phi is something different than Pi. I know the whole e^(ix) = (cosx + i*sinx) from differential equations.
Never heard of that. What is it?
https://en.wikipedia.org/wiki/Euler's_formula
-
Yeah, but rumborak was talking about e^(i*phi). Phi is something different than Pi. I know the whole e^(ix) = (cosx + i*sinx) from differential equations.
Never heard of that. What is it?
https://en.wikipedia.org/wiki/Euler's_formula
I meant as referring to e^(i*phi) which according to Jamesman is different to Euler's formula? eh
-
Yeah, but rumborak was talking about e^(i*phi). Phi is something different than Pi. I know the whole e^(ix) = (cosx + i*sinx) from differential equations.
Well yes but if you take Phi = Pi then you get that famous formula. I don't think you would learn about one but not the other...
-
I thought Phi was something different...or did rumborak make a typo?
-
Phi just means the angle... Like theta or so.
I think I get what you mean... Phi is also the golden ratio.
-
Yeah, I thought it might be some other constant...because apparently there are a bunch of them out there represented by Greek letters that I don't know about. :lol
-
I guess 26 just isn't enough... :)
-
I HAS A MATHS QUESTION
but it's for a class to take
what do you guys think about a class called Survey of Calculus? I just need a math credit and I'm not majoring in anything math related, but i don't know anything about calculus and this is pretty much the only class available.
-
What's the course description say?
-
Survey usually means ree-ree. I'd take it.
-
What's the course description say?
Prerequisite: Algrebra (which I have taken)
Rates of change, derivatives, and integration with applications to business are studied.
-
I'd take it. It should be really easy.
-
What's the course description say?
Prerequisite: Algrebra (which I have taken)
Rates of change, derivatives, and integration with applications to business are studied.
Sounds like it's basically introductory calculus...
I'd take it. It should be really easy.
...which means it could be really easy or it could be a total bitch - it completely depends on the teacher.
-
Given you only have algebra background, it shouldn't be too bad. "Real" Calculus would require trigonometry and pre-calculus, so you should be ok.
-
...which means it could be really easy or it could be a total bitch - it completely depends on the teacher.
This. I took AP Calc as a Junior, which should've been easy, but the teacher also happened to be the bitchy track team coach (Our school is in a rural town filled with hicks, so there's not too much need for book learnin).
She went over shit in the most complex way possible, and I ended up as one of two students, in a class of about sixteen, to pass the AP exam. Even though it was just simple integrals and derivatives...
Then I took a Dual Enrollment Calc II course at a technical college, and it was the easiest class I had that semester. The teacher really matters when you get up to anything complex.
-
Given you only have algebra background, it shouldn't be too bad. "Real" Calculus would require trigonometry and pre-calculus, so you should be ok.
This. It sounds like it isn't a rigorous course in calculus, so it should be Calculus Lite.
-
yeah there are other calculus classes but they are all called Calculus with Analytic Geometry
-
Yeah, that is a standard Calc 1 class, which you need trig and precalc for.
Although it makes me scratch my head sometimes because people at my college can skip trig and go straight to Calc 1, and when those students get to Calc 2, they get really lost.
-
So is it pretty much agreed that I should take it? I'm all for putting in the effort for the class, I just didn't want to take something way above my level of knowledge.
-
You should be fine as far as knowing what you need to know.
-
You should be fine. A lot of the introductory calculus concepts are simply an expansion of algebra. Based on your description, you won't have to do crazy stuff with trigonometry and the unit circle. I'm not sure how much they'll cover derivatives and integration, but they're just procedures you have to memorize, and if the professor does a good job, you'll understand the concept of what they mean.
-
What math classes have you taken exactly? Algebra I and II? Geometry? I think you should be fine if it is just a light version of the subject.
-
I've had the standard college Algebra class (as opposed to the remedial/intermediate/introductory ones) and I was o.k. at it. I was really good at Geometry in high school though.
I'll go for this but hopefully I can get a statistics class or something haha
-
Good math discussions in this thread. :)
I have my Calc III final this Thursday. It'll be full of three-dimensional vector calculus and double integral stuff. Loads of fun.
-
I dislike all things ending in -ometry. Algebra is the shit. I could go on forever in that stuff.
-
I've had the standard college Algebra class (as opposed to the remedial/intermediate/introductory ones) and I was o.k. at it. I was really good at Geometry in high school though.
I'll go for this but hopefully I can get a statistics class or something haha
Statistics is cool. it is half dissecting the problem (which isn't too bad) and half actual math to do.
Calc III is fun stuff...I am going through it all again on my own because a bunch students here at the college will be coming to me for some help. :lol
I dislike all things ending in -ometry. Algebra is the shit. I could go on forever in that stuff.
It's cool though, in calculus, you see algebra, geometry and trig come together very nicely. It's beautiful.
-
Good math discussions in this thread. :)
I have my Calc III final this Thursday. It'll be full of three-dimensional vector calculus and double integral stuff. Loads of fun.
I just started my Vector Calculus summer course yesterday.. Hopefully it goes well.
Good luck to you tomorrow!
Given you only have algebra background, it shouldn't be too bad. "Real" Calculus would require trigonometry and pre-calculus, so you should be ok.
I'm a chem major in uni, so I have to take several calculus and algebra classes, all of which have been mentioned/alluded to in this thread. However, all of my uni friends are bio majors, and only have to take one calc class, which I recently discovered did not cover anything having to do with trigonometry.
I was stunned. And immensely jealous.
-
Calculus is somthing you have to do to get to the physics. :p
-
^For real. I've never taken physics in any form(I really should), but it's cool to help the physics students at the college with problems, even if I don't fully understand what is going on.
-
^For real. I've never taken physics in any form(I really should), but it's cool to help the physics students at the college with problems, even if I don't fully understand what is going on.
They probably don't either.
-
I'm not looking forward to calc just because of these things. I adore algebra. The shit we are doing now, there is a good 3-4:1 ratio of variables to real numbers. That is when you know everything is right in the math world.
Once you get the basics of calculus down, it becomes a breeze!
-
Until it gets hard again, that is.
-
Definitely. Triple integrals are bitches. :lol
-
I thought double and triple integrals were nice.
It was vector analysis that confused me, but that is more due to my professor being so pressed for time at the end that she didn't really teach it to us. Sucks, because I occasionally get asked about line integrals and I am unsure of what they are at the moment (working toward that section now).
-
Yeah, line and surface integrals of vector fields aren't my cup of tea either.
-
Definitely. Triple integrals are bitches. :lol
Nah, that's just doing the same process again and again, basically.
Yeah, line and surface integrals of vector fields aren't my cup of tea either.
Now those I didn't like either.
EDIT: Although, for some reason, integrals and differential equations become very important when analyzing electrical circuits. Since I'm currently taking circuit analysis, I am not amused.
-
Yeah. I also have this course called "Electromagnetism and optica" and it seems like all we ever do is solve integrals and differentials. Stupid Kirchhoff laws.
-
I never even learned about surface integrals
-
Yeah. I also have this course called "Electromagnetism and optica" and it seems like all we ever do is solve integrals and differentials. Stupid Kirchhoff laws.
If they stayed only with KCL and KVL I would love it! But on circuit analysis 2 (yeah, another one) they bring Laplace transforms! FML
-
I never even learned about surface integrals
It's basically like a double integral but instead of regular integrals they are line integrals.
-
Yeah. I also have this course called "Electromagnetism and optica" and it seems like all we ever do is solve integrals and differentials. Stupid Kirchhoff laws.
If they stayed only with KCL and KVL I would love it! But on circuit analysis 2 (yeah, another one) they bring Laplace transforms! FML
That's for next semester I think.
-
Yeah. I also have this course called "Electromagnetism and optica" and it seems like all we ever do is solve integrals and differentials. Stupid Kirchhoff laws.
More like Jackhoff laws, amirite?
-
Yeah. I also have this course called "Electromagnetism and optica" and it seems like all we ever do is solve integrals and differentials. Stupid Kirchhoff laws.
That's the way physics roll. It's 85% math.
-
Yeah. I also have this course called "Electromagnetism and optica" and it seems like all we ever do is solve integrals and differentials. Stupid Kirchhoff laws.
That's the way physics roll. It's 85% math.
I love math!