Math Is Fun Forum
You are not logged in.
- Topics: Active | Unanswered
#376 Help Me ! » Some questions regarding Rolle's Theorem and MVT. » 2007-11-16 13:47:40
- LuisRodg
- Replies: 8
Hello everyone.
Today in class we were introduced to the Rolle's Theorem in which it states that if a function f(x) is continuous on [a,b] and differentiable on (a,b) then there exists a C in (a,b) in which f'(C) = 0. Now, I understand this perfectly fine but Im wondering why do I need a theorem to tell me that something exists if I can just find the derivative, set it equal to zero and I will see myself if it has a C inside of (a,b) in which f'(C)=0. I dont know but that theorem seems kind of redundant and the professor really emphasized on it as being really important.
We were also introduced to the Mean-Value Theorem which is giving me a little more trouble grasping it. The MVT states that if f a function f(x) is continuous on [a,b] and differentiable on (a,b) then there exists a C in (a,b) in which f'(C) = (f(b)-f(a))/(b-a)
Lets say that:
Z = (f(b)-f(a))/(b-a)
So I know that there exists a C in (a,b) in which f'(C) = Z. And? What does that tell me? How does that help me?
Thanks guys. Just try to clear up my head please. I love math and I usually learn it by understanding its concepts rather than memorizing some formulas so when im asked to just memorize and im not told how that helps me...It just makes it harder for me.
Thanks.
#377 Re: Help Me ! » Need some help on a Calculus problem. » 2007-11-12 13:53:58
Ok got it. I just never learned that a function is symmetrical if f(k+x)=f(k-x)
What about this:
Show that y=x+3 is an oblique asymptote of the graph of f(x)=x^2/(x-3)
I dont even know what an oblique asymptote is. I guess my problem lies in pre-calc and not calculus itself.
#378 Help Me ! » Need some help on a Calculus problem. » 2007-11-12 07:55:54
- LuisRodg
- Replies: 5
It says:
Prove that if a != b then f(x) = 1 \ ((x-a)(x-b)) is symmetric about x = (a+b)/2
I have no idea how to go on about this problem. I took the derivative of f(x) and found out that x = (a+b)/2 is when the derivative is equal to zero. But what does that tell me?
Thanks.
#379 Re: Help Me ! » percentage » 2007-11-09 07:09:33
One way you can understand this is to setup percentages as ratios of fractions.
You can say:
0.15/2.50 = x/100
In here your saying that 0.15 is to 2.50 as x is to 100. In here x represents the percentage increase. If you solve for x then:
x = 15/2.5
x = 6
which gives you the percentage.
#380 Re: Dark Discussions at Cafe Infinity » Q20 » 2007-11-09 04:03:23
Blah!
i say from now on, if the person is alive, we use a binary search to pinpoint his/her exact age in the first seven questions!
I know so little about rock artists, I can't even think of what to ask now!
Exactly the same here. I just dont know anything about music at all.
#381 Re: Dark Discussions at Cafe Infinity » University of Miami - Graduate School - Mathematics » 2007-11-07 13:37:47
Thanks Ricky. Even though UM is heavily focuses on the areas you mentioned, I found a professor which is doing research on a topic that would interest me:
Numerical Analysis, Computer Science, Computational Mathematics
What I mean is, even if the majority of the faculty is focuses on something but I find one professor which is doing something different and fits me, then I should be ok?
Thanks for all the info. I still got some years to go.
#382 Re: Euler Avenue » GRE subject test » 2007-11-07 11:40:48
I see. Im still a freshman so i got a long way to go but hey, I heard time flies in college.
When I entered college I came with the idea of doing a Double Major in Math and CS but some of the classes that are required for the CS major I simply hate which require public speaking, presentations etc. So I decided to drop the CS major and actually just minor in it which doesnt require any of the useless extra classes so Im hoping to do a math major and cs minor.
You mentioned about getting into a a Phd program right after you graduate. I have similar ideas but also a lot of doubts since I dont know if one must first get a MS and then a Phd or just get the Phd straight. Whats the best route in your opinion?
Im currently attending FIU here in Miami and I would love to go to UM (University of Miami) for Graduate School. I was researching a bit and it shows that if you apply for the Phd and request financial assistance they give you a tuition waiver for 18 credits (each credit costs $1300 so you do the math 
) and also an stipend ranging from 15-17k for being a Teaching Assistance. That would be so PERFECT for me. They also dont require the GRE Math subject test but I think im still gonna take it just to see how im doing. Lets see what happens. As of right now I would love to go to UM's Grad School but then again im just a freshman.
Heres a post I made about it:
http://www.mathisfunforum.com/viewtopic.php?id=8598
Been nice talking to you Ricky.
#383 Re: Dark Discussions at Cafe Infinity » Q20 » 2007-11-07 08:40:49
Dont use up a question for that! :d
#384 Re: Dark Discussions at Cafe Infinity » Q20 » 2007-11-07 08:26:15
You have made this too hard! hehe
#385 Dark Discussions at Cafe Infinity » University of Miami - Graduate School - Mathematics » 2007-11-07 06:13:11
- LuisRodg
- Replies: 4
Hello guys. Even though the discussions carried in this forum dont have anything to do with college etc, im going to make a post about it.
I am currently a freshman at Florida International University (FIU) in Miami doing a Mathematics major with a minor in Computer Science. I LOVE math and am very sure that is what I want to do for Grad school.
I was wondering how good the math department at UM is? I have lived in Miami for practically all my life and that is the reason I am going to FIU because I wanted to stay local and I also want to do the same for grad school therefore the reason for me choosing UM.
So I was wondering how tough is it to enter into UM's Grad school doing a MS/Phd in Mathematics. Also, how much does UM or math departments from any school weight your grades on classes which aren't from your major? For example, I am very confident that I am going to have a 4.0 in my math classes (major GPA) but I suspect I will have a couple C's and B's from other areas but always straight A in math.
Any opinions?
Also, should one go straight to a Phd after your BS or go in order BS -> MS -> Phd?
Thanks.
#386 Re: Dark Discussions at Cafe Infinity » Q20 » 2007-11-07 06:09:00
11. Is he from Italy?
#387 Re: Euler Avenue » GRE subject test » 2007-11-07 05:58:12
Hehe. I guess we are similar. I behave the same when taking tests or doing something that requires my total attention. Its like, my mind is totally concentrated on what im doing but its like my body starts moving to relieve the stress, like I start bumping my legs, making weird faces etc.
Anyways, by knowing your taking the GRE I would assume you are an undergrad student, right? By looking at some of your posts I actually expected you to hold a Phd in math or something because you seem very knowledgeable. What college you going to?
#388 Re: Dark Discussions at Cafe Infinity » Q20 » 2007-11-07 04:00:15
9. Does he currently live in Europe?
PS: I like this game. I want to be the next one to answer the questions please? Pretty please? 
#389 Re: Dark Discussions at Cafe Infinity » Q20 » 2007-11-07 03:50:10
To mikau,
I never said Einstein was not involved in mathematics.but but...you DID!
post#6 by MathsIsFun "Was he involved in mathematics?"
post#7 by ganesh: "no"
I agree. The answer to that question should had been a "yes". Although as you said, he was not a "Mathematician" he was indeed very much "involved in mathematics".
#390 Re: Dark Discussions at Cafe Infinity » Q20 » 2007-11-07 02:40:58
6. Is he white?
#391 Re: Dark Discussions at Cafe Infinity » The math class of darkness... » 2007-11-07 01:20:09
Im fairly confused...
#392 Re: Euler Avenue » GRE subject test » 2007-11-06 14:18:52
Ricky. Sorry for digging up this old topic but I was just interested in it. Did you actually take the GRE? How did you do? I am just a freshman right now doing a Math major and Im just taking Calculus I and I was fairly intimidated by that test...I hope the next 4 years of math classes prepare for it.
#393 Re: Puzzles and Games » Lateral thinking puzzles » 2007-11-05 03:16:54
2. He was born by his parents doing a 69 and then died on 89...lol thats just my pervert mind speaking.
#394 Re: Dark Discussions at Cafe Infinity » William James Sidis, Probably the Greatest Genius who ever lived » 2007-11-03 10:01:14
Amazing. I wish I was that smart.
#395 Re: Jokes » marriage » 2007-11-02 01:27:29
Excellent lol!
#396 Re: Jokes » A Mathematician, an Engineer and a Physicist Staying in a Hotel » 2007-11-02 01:13:36
LuisRodg wrote:I have seen countless of "mathematician jokes" in which the punch-line is always "Ah,, a solution exists!"
Why is that?
I have no idea. I can't see why people would think that that is the logic of mathematical concepts and people.
Maybe its because in Mathematics its always about being sure that "a solution exists" without actually knowing what the solution is but it suffices that it exists...I dont know Im just speaking my mind.
#397 Re: Jokes » The angry genie! » 2007-11-01 14:02:53
I heard it before but instead of saying "I've always wanted to donate a kidney..." I seen it with "I'd now like a mild heart-attack"
Works the same though.
#398 Re: This is Cool » Microsoft Math 3.0?? » 2007-10-31 09:20:07
microsoft math 3.0 is great and user friendly, but it really doesn't rank anywhere near MATLAB in terms of capabilities.
Or Mathematica
#399 Re: Jokes » My generation Vs yours » 2007-10-31 00:06:34
Meh 
young generation > old generation
#400 Re: Help Me ! » Becoming a Mathematician... » 2007-10-26 00:43:12
Thanks guys.
Following what you guys said, my body and mind tells me I desire to be a Mathematician, I have never had a doubt about it except for this very issue that I decided to make this topic.
So like you guys said, keep going and see how it goes. Up to now it's been great.
Btw, I just received my second test grade on Calculus and I scored a 100% ! Only A in the whole class. Im so excited. Class average was a 41.75 so you can figure how the badly other people did...
Anyways, why is Real Analysis always talked about as the defining point of hard math. For example, I have heard that Real Analysis is the class that lets you know if your able to be a Mathematician or not. Does this class deserve so much credit? Dont know if you get my question.
Well guys, thanks a lot/.