*math Help!*

[jdm_eg6]

Okay this may be simple, it might not! but iam ready to shot somone in the face RIGHT NOW! its bothering me soo much here it is:

find the limit as X approaches 2 of:

X^4 - 16
------------
X^3 - 8

Anyone? PLEASE!

[no_joke]

What course is this for?

[Crymson]

You need to factor.

[Zero102]

Does L'Hopital's rule apply here?....
lim(d(X^4 - 16)/d(X^3 - 8)) = lim((X^4 - 16)/(X^3 - 8))

Been a while since I did this, but maybe......
lim((4X^3 - 16)/(3X^2 - 8)) as x-->2 = (4*8 - 16)/(3*4 - 8) = 16/4 = 4?

Or am I applying this all wrong?

[jdm_eg6]

AMAT 217- Applied mathimatics At the UofC (applied doesnt mean dumb like highschool its Higher level)

[Crymson]

It's been a long time since I did calculus 100, but they're difference of squares.

So youll end up with like (x^2-4)(x^2+4)/(x-2)(X^2+2x+4) or something like that, and the components will cancel, leving you with a quotent non 0, or everything will cancel, or something.

Forgive me, it's been a long time.

[Crymson]

Originally posted by Zero102
Does L'Hopital's rule apply here?....
lim(d(X^4 - 16)/d(X^3 - 8)) = lim((X^4 - 16)/(X^3 - 8))

Been a while since I did this, but maybe......
lim((4X^3 - 16)/(3X^2 - 8)) as x-->2 = (4*8 - 16)/(3*4 - 8) = 16/4 = 4?

Or am I applying this all wrong?

L'hopita's rule does apply, but remeber back to first year calc. You have to learn limits before derivatives, so you're not allowed to use it yet.

[jdm_eg6]

ZERO 102, i think your trying to do the qutient rule, but wrong answer. Its really destroying me!!! I tried it too and got 1... which is also wrong..

Crymson: Factoring... sure then how? ive tried and nothing cancels, and btw how do i factor the bottom!!!

[jdm_eg6]

Ive done Derivatives to the bajillionth degree, and anti derivatives until my gut burst.... i understand that. but iam just horrible at limits, and this one is pissing me off haha

[jdm_eg6]

Wait, i think you might have applied the rule wrong b.c when you find the derivative of the functions you have to drop the constants like 16 and 8 that way you have 32/12 which is equal to 8/3 which is the answer but WTF!!! i have never learnt that rule!

[punky]

I think there's a L'hopital rule that says, lim(x->#) = fx1/fx2.
then the limit is also true for, fx1'/fx2'. or something along that line.
Basically you take the derivative of the top and bottom, and sub a value in for x.
Somebody corrects me if i'm wrong
4x^3
-------
3x^2
sub in 2 for x,
we get 32/12.

[xcelr8]

i got 8/3 too, while using derivatives

[xcelr8]

The answer is for sure 8/3, I threw it into my graphing calculator, and it worked out. Now you have to find out how to do it the long way.

[punky]

sweet some one got the same answer as me:D
but limits isnt that hard.
the hard part is simplifying the equations whenever possible.
things tends to cancel out nicely.
and L'hopital's rule is very helpful as well

[Crymson]

Originally posted by jdm_eg6
ZERO 102, i think your trying to do the qutient rule, but wrong answer. Its really destroying me!!! I tried it too and got 1... which is also wrong..

Crymson: Factoring... sure then how? ive tried and nothing cancels, and btw how do i factor the bottom!!!

Bottom is a difference of cubes

x^3 – 8 = x^3 – 2^3 = (x – 2)(x2 + 2x + 2^2)

You guys are so obviously all engineers, calculators and l'hopitals when a little algebra is all that's needed.

[punky]

the long way i would guess is you expand the two top and bottom using binomial theorem (is that the thing u use to expand any given equation??) then something probally will cancel with the bottom (x-2) ??
then you just sub in 2.

[sh0ko]

is the answer 16/15???

[jdm_eg6]

thats what iamthinken...

[sh0ko]

is it or nto?! hahaha did u check ur pm man?!

[jdm_eg6]

Sh0ko... no its 8/3

[sh0ko]

haha i remmeber this question from last year

[Crymson]

It's 8/3

(x^4 - 16) breaks down to (x^2 +4)(x^2-4), which breaks down to (x^2 + 4) (x-2)(x+2) because it's a difference of squares

(x^3 - 8) breaks down to (x -2)(x^2 +2x + 4) because it's a difference of cubes

the x-2's cancel, sub in 2 for x, and you get 32/12 aka 8/3

[sh0ko]

yah haha i was reading some guys wrong i read 22 instead of 2^2 for the bottom man! otherwise everything else was correct sorry about that dude

[jdm_eg6]

Crymson, Thanks for putting me back into the frame of mind!!! DUH! i always missed that in Gr12 and i have to change gears again back to calc'ing it!! THANKS GUYS!!! i love beyond!!! HAHAH

[camby]

Originally posted by jdm_eg6
Wait, i think you might have applied the rule wrong b.c when you find the derivative of the functions you have to drop the constants like 16 and 8 that way you have 32/12 which is equal to 8/3 which is the answer but WTF!!! i have never learnt that rule!

You probably went to a shitty school. Doesn't matter since this course is a refresher course to make sure all your frosh are on the same page.

[turbotrip]

Originally posted by jdm_eg6
applied doesnt mean dumb like highschool its Higher level

sure buddy, only retards go into applied math, if u were smart u wouldve been in PMAT 217 (pure math), dont try to pass of an easy course as a higher level course :rolleyes: :D

[punky]

yup crymson has got it.
I was taking the same route except that he realized that it's a difference of square, where as i did long divisions. the answers came out the same.
anyone here in ENGG at UC?

[punky]

I wouldn't say AMAT217 is an easy course. The material is pretty much math31 + some more. But the exams are freaky hard.

[jdm_eg6]

sure buddy, only retards go into applied math, if u were smart u wouldve been in PMAT 217 (pure math), dont try to pass of an easy course as a higher level course
....

i hope that your kidding buddy... you must... never mind i wont start ill leave it at that... lets just hope its sarcasm because it will be us thats laughing.


You probably went to a shitty school. Doesn't matter since this course is a refresher course to make sure all your frosh are on the same page.


Shitty school yes, but my teacher was great he tought outside of the cirriculum and helped me be a much better math student through being a great help and always being there to help me accel, but lets chill with the horrid comments.

[Crymson]

When i went to university there was applied math, honours math, and just math.

The honour math was for physics, math, and engineering physics students, focused primarily on proofs of theorems. I took these and got a stunning 3 out of 40 on a midterm once. That was a glorious day. Managed to pass though, because the engineering students complained and their college was important and they got listened to, so we got the grades tossed out, and another professor made the final exam.

the applied math was the same material as the honours math, but it was taught with a focus on problem solving and "real world" scenarios, and that was taken by the majority of engineering students.

The "just math" courses were usually taken by either group of students, who happend to be out of synch with their program an needed the material, but needed a waiver for it to be counted as a pre-req for a highter level either applied or honours version of that mathematical branch, usually the 3rd year partial derivative and vector calc courses.

[mo_money2supe]

Originally posted by turbotrip


sure buddy, only retards go into applied math, if u were smart u wouldve been in PMAT 217 (pure math), dont try to pass of an easy course as a higher level course :rolleyes: :D

I hope you do realize this is an Engg course. Not to say that Engineers are be all, and are all, though I am one myself, but IF there was an equivalent PMAT 217, I guarantee you AMAT 217 will be x-times harder in difficulty (where x>0 obviously :D ).

EDIT: To the original poster, JDM_EG6, if you find that there's a question that seems beyond hard relative to what you've been taught, then try "dumbing" yourself down. What I mean is, just as Crymson stated, don't try to make it harder than it is. As I've found out over the years, often times, a hard question is often solvable by means of an easy answer.

[punky]

If you guys need 1st, 2nd year engg book let me know~

[jdm_eg6]

^^ Thank you mo_money2supe

Although i was ignorant like ghetto fly boi too once and laughed at my teacher when he said he majored in applied math, then he explained it to us... Ignorance is truely bliss..

[jdm_eg6]

anyway, ive received 100000 ways to solve this question, my favorite was difference of cubes, cancel and solve. Thanks again everyone!

[turbotrip]

Originally posted by mo_money2supe

but IF there was an equivalent PMAT 217, I guarantee you AMAT 217 will be x-times harder in difficulty (where x>0 obviously :D ).


u can say whatever u want but all the smart pepple know that PMAT is where its at, and those who cant get into PMAT 217 have to settle for AMAT 217. I could probably get an A in Applied Math 217 no problem.

oh and jdm eg6, ignorance truly is bliss

[dj_honda]

Originally posted by jdm_eg6
....

i hope that your kidding buddy... you must... never mind i wont start ill leave it at that... lets just hope its sarcasm because it will be us thats laughing.



Shitty school yes, but my teacher was great he tought outside of the cirriculum and helped me be a much better math student through being a great help and always being there to help me accel, but lets chill with the horrid comments. \

too bad your english teacher didn't teach outside of the curriculum to help you excel at spelling. :D ;)

[camby]

Yeah its good that you got your question answered. Just keep in mind this course is a refresher from Math31. If some of the material is new or whatever, it is because your highschool teacher didn't teach you enough stuff. Also, AMAT217 is not an engineering course. It is simply a math course; probably the same as PMAT217; maybe easier.

[mo_money2supe]

Originally posted by turbotrip


u can say whatever u want but all the smart pepple know that PMAT is where its at, and those who cant get into PMAT 217 have to settle for AMAT 217. I could probably get an A in Applied Math 217 no problem.

oh and jdm eg6, ignorance truly is bliss

Like you say, "u can say whatever u want," but for Engineers at U of C, AMAT 217's the only _MAT 217 they can take. I honestly hope you're either playing us and just joking, or are still in High School and don't know what you're talking about. :nut:

Nonetheless, the question has been answered, I think this thread is finished.

[msommers]

Then there is also math 221, which isn't too bad so far but my teacher is like 80 and also wrote the textbook...lovely. It's funny how I can pick out most of the engineering students however:D

[Team_Mclaren]

Originally posted by turbotrip


u can say whatever u want but all the smart pepple know that PMAT is where its at, and those who cant get into PMAT 217 have to settle for AMAT 217. I could probably get an A in Applied Math 217 no problem.

oh and jdm eg6, ignorance truly is bliss

did you take amat309? are you a math major? amat and pmat are pretty different? no?

[turbotrip]

^I dont know, im still in high school but hope to be able to take PMAT 217 one day...

[l/l/rX]

Originally posted by turbotrip
^I dont know, im still in high school but hope to be able to take PMAT 217 one day...

i hope you were kidding when you say you are in high school. this thread is going to go bad fast.

[Crymson]

Move it to ask leo so they can have a vulgar math-off.

[Bongo]

u can say whatever u want but all the smart pepple know that PMAT is where its at, and those who cant get into PMAT 217 have to settle for AMAT 217. I could probably get an A in Applied Math 217 no problem.

oh and jdm eg6, ignorance truly is bliss


There is no PMAT 217 just to let you know. Link (http://www.math.ucalgary.ca/education/undergrad/courselisting.php?termid=41&coursetypeid=4&courseid=)

Might want to check on that before you start stirring shit up.

In the future, use L'Hopitals rule, or break it down like crymson did. You did pick up Elsabrouty's notes at ESS didn't you?

[turbotrip]

Originally posted by Bongo


There is no PMAT 217 just to let you know. Link (http://www.math.ucalgary.ca/education/undergrad/courselisting.php?termid=41&coursetypeid=4&courseid=)

Might want to check on that before you start stirring shit up.


haha oh shit i didnt even know PMAT was a real course name, i just made that shit up cuz of pure math and applied math lol.

I was just playing with this kid whose all high on getting into engineering and "isnt dumb" because he is "higher level" :rofl: :rofl:



Originally posted by Crymson
Move it to ask leo so they can have a vulgar math-off.

Hahaha lets do this, using my newly acquired PMAT 217 skills I would rape and violate everyone lol

Oh and BTW for anyone whose still confused Im not in high school and have taken AMAT 217 :)

[samo147]

One of the easier 1st year courses good luck

[punky]

^ yup!
wait, you still got AMAT219, AMAT307 and or 309. Not to mention other engineering courses.

AMAT isnt easy, neither is it top notch math (At the level i've taken that is). It's just what works very well with engineering applications.

[Zero102]

Whoops, I totall fucked applying L'Hopitals rule... at least I came up with the right way to solve it?... F for effort? ;)
I forgot to drop the constants when I took the derivative. It's been about 2 years since I have taken any math classes, so forgive me. It's all been CPSC and ASTR/PHYS lately.

[bball2]

Maybe its just me but amat 217 has been pretty useless thus far, way slower pace then high school?