Senior Members

92

10 Neutral

• Rank
Meson

## Profile Information

• Location
Maryland, USA
• Interests
Cars, Music, Tattoos
• College Major/Degree
Indiana University of PA..BS Applied Mathematics (almost)
• Favorite Area of Science
Math
1. ## Help me help a kid with math (or, justifying negative exponents)

panic has it right, its simply convention that maintains continuity in notation. THe eastiest example is this... x^3/x^2 = x^(3-2) = x^1= x x^3/x^4 = x^(3-4) = x^(-1) so what is x^(-1)? well if you write it out on paper is cross out fators its a little easier to see, but this should give you the idea. x^3/x^4 = (x*x*x)/(x*x*x*x) notice, three of the x's on top cancel out with 3 on bottom so that means that x^3/x^4 = (x*x*x)/(x*x*x*x) = 1/x So, because of this, we adopt the notation x^(-n) = 1/x^n in order to maintain uniform notation.
2. ## Looking for a math article with a proof in it

I have to do a presentation on a math article for a senior topics class in a couple weeks and i was wondering if anyone had a good article on hyperbolic space that has a proof in it that is fairly graspable. Or if anyone has any interesting article so long as it has a proof in it and is not super long. Thanks guys Nathan
3. ## Help me help a kid with math (or, justifying negative exponents)

it has to do with maintaining continuity of notation. Same with numbers to the zero power equaling 1.
4. ## Need Quick Help to Solve a diff eq

can someone solve this system for me...its killing me to do it by hand and i dont have my hands on any software x'' - x' + y' + 2y = t y'' + x' - 2x - y = cos2t where x and y are functions of t i just need the general solutions for x and y.....thanks fellas
5. ## Diff Eq help

thanks bro, that was really helpful
6. ## Diff Eq help

thanks bro, that was really helpful
7. ## Diff Eq help

thanks a lot man, that realy helped me out, good to see i'm on the right track....did you happen to maple the 2nd one? Also, i'm getting screwed up on something else, same section, but i dont remember if the derivative of x'/2 is x''/2 or x''...any help there?
8. ## Diff Eq help

thanks a lot man, that realy helped me out, good to see i'm on the right track....did you happen to maple the 2nd one? Also, i'm getting screwed up on something else, same section, but i dont remember if the derivative of x'/2 is x''/2 or x''...any help there?
9. ## Diff Eq help

if anyone is on and able to check my work on these couple diff eqs i would really appreciate it. The prof doesnt assign problems with solutions so i cant ever check my work . That is frustrating....heres a couple x' = 3x - 2y + sin(t) y' = 4x - y - cos(t) i used the differential operator and the method of undetermined coeffcients to get this answer..dont think its right because its so ugly x = [e^(t)] * [Acos(2t) + Bsin(2t)] - (1/10)sin(t) + (7/10)cos(t) y = [Ce^(t)] * [Dcos(2t) + Esin(2t)] + (11/10)sin(t) + (3/10)cos(t) And, if you are up to it, heres another one...D is the differential operator (D-3)[x] + (D-1)[y] = t (D+1)[x] + (D+4)[y] = 1 got answers useing the same method as above... y = Ae^(11t) + (1/10)t + (3/11) x = Be^(3t) - (9/20)t + (19/330) Thanks for anyone who responds...anyone going to IUP should avoid Dr. Kuo, lol, check her rating on http://www.ratemyproffesor.com and i've had her for 4 classes, she is terrible...my only Cs in math
10. ## Diff Eq help

if anyone is on and able to check my work on these couple diff eqs i would really appreciate it. The prof doesnt assign problems with solutions so i cant ever check my work . That is frustrating....heres a couple x' = 3x - 2y + sin(t) y' = 4x - y - cos(t) i used the differential operator and the method of undetermined coeffcients to get this answer..dont think its right because its so ugly x = [e^(t)] * [Acos(2t) + Bsin(2t)] - (1/10)sin(t) + (7/10)cos(t) y = [Ce^(t)] * [Dcos(2t) + Esin(2t)] + (11/10)sin(t) + (3/10)cos(t) And, if you are up to it, heres another one...D is the differential operator (D-3)[x] + (D-1)[y] = t (D+1)[x] + (D+4)[y] = 1 got answers useing the same method as above... y = Ae^(11t) + (1/10)t + (3/11) x = Be^(3t) - (9/20)t + (19/330) Thanks for anyone who responds...anyone going to IUP should avoid Dr. Kuo, lol, check her rating on http://www.ratemyproffesor.com and i've had her for 4 classes, she is terrible...my only Cs in math
11. ## What is topology?

ah, i know a little about homomorphisms, so i think i know a little about what it is now...at least enough to tell people when they ask
12. ## What is topology?

well it sounds pretty cool, though i only have a bit more of an understanding than i do now, lol....i'll post my findings while i'm taking the class
13. ## What is topology?

gonna take a class next semester on toplogy and i was wondering what it was. The course description was...less than descripted, damn mathmeticians

15. ## Modular Arithmetic

i am proficient in linear algebra...though forigve me if this post is short, as i just finsihed doing 6 sections worth of diff eq and proofs homework and my brain in a little fried. We just started doing rings, could you give me something to look for in the lectures that might help me figure out what set product modulo is?
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