Login






BMW Garage  BMW Meets  Register  Search  Today's Posts  Mark Forums Read 

BMW 3Series (E90 E92) Forum
>
Calculus I problem


09102013, 11:58 AM  #1 
Grozniy
54
Rep 2,600
Posts 
Calculus I problem
Anyone good in Calculus?
I solved the problem, but I am not sure if I am correct or not. The problem states: Discuss the continuity of f(x)= (x^2+2x3)/(x+3) on interval [5, 2] Since polynomials are continuous everywhere, this particular function is not defined at x=3. Do i just state that the function is continuous everywhere except at x=3 ? Do I have to find one sided limits as well? f(5)= {(5)^2+2(5)3)}/{(2+3)}= 6 f(2) = {(2)^2+2(2)3)}/{(2+3)} = 1 lim x>5+ so I find the limit from the right side and get = 6 lim x>2 and I get = 1 since, my function values equal the limits...does it say the function is continuous everywhere except at x=3?
__________________
fatman

09102013, 12:37 PM  #2 
Private First Class
5
Rep 142
Posts 
EDIT I'm wrong
EDIT 2 the limit exists when 5<x<3 and 3<x<2 The limit is defined 6<f(x)<0 and 0<f(x)<1 discontinuity when x=3 let's go with that. Last edited by RandomHero; 09102013 at 01:12 PM. 
Appreciate
0

09102013, 01:42 PM  #4 
Major General
103
Rep 5,235
Posts 
After 10 years at a major financial institution, I can confirm that this will never be used in your real life.
__________________
The views and opinions expressed in this post are those of the author and do not necessarily reflect the official policy or position of Bimmerpost.
2010 S4 Current  2010 BMW 135i Retired  2006 Lotus Exige Retired 
Appreciate
0

09102013, 02:02 PM  #5 
Captain
158
Rep 683
Posts 
After a year of working as an engineer I can also confirm that this will not be needed. With that being said, I forgot everything from Calc I. Sorry

Appreciate
0

09102013, 02:20 PM  #6  
Captain
56
Rep 803
Posts 
Quote:
Example [Infinity to 4] [2 to +Infinity]
__________________
WHO'S THE BOSS


Appreciate
0

09102013, 02:24 PM  #7 
Captain
56
Rep 803
Posts 
Also, this information maybe needed later in life. For example i never really paid attention in Trigonometry class.
Until recently, i had to write a function that involved trig and calc. I did some personal research and I thought my self much better than i learned in school.
__________________
WHO'S THE BOSS

Appreciate
0

09102013, 02:42 PM  #8 
Captain
11
Rep 769
Posts 
You would simply state that the function is continuous over the ranges [5,3) and (3,2]. More generally, the function is continuous everywhere except for x=3 as you stated, which can formally be written as continuous over the ranges (Inf,3) and (3,+Inf). Just remember, to be rigorous, that you need to use the notation of open set "( )" and closed set "[ ]" to be correct. Infinity is always used with the open set symbol as it can't be contained.
And yea... this stuff is probably never going to be useful to you. The sort of thinking MAY be useful in some areas but it's rare.
__________________

Appreciate
0

09102013, 02:59 PM  #9  
Captain
56
Rep 803
Posts 
Quote:
__________________
WHO'S THE BOSS


Appreciate
0

09102013, 03:31 PM  #11 
Lieutenant Colonel
38
Rep 1,732
Posts 

Appreciate
0

09102013, 03:35 PM  #12  
Captain
158
Rep 683
Posts 
Quote:


Appreciate
0

09102013, 03:37 PM  #13 
Captain
56
Rep 803
Posts 
Discrete Math is my fav.
__________________
WHO'S THE BOSS

Appreciate
0

09102013, 03:38 PM  #14 
Captain
158
Rep 683
Posts 
Worst class ever: Calc II. Fuck that Taylor Series bullshit

Appreciate
0

09102013, 06:38 PM  #17 
Major
80
Rep 1,403
Posts 
I can confirm as we'll this shit will never be used as an analyst at a Fortune 100 company. Fucking waste of time....I took calc 3...bullshit unless you're going to be a math teacher or some shit.

Appreciate
0

09112013, 07:21 AM  #18 
Captain
158
Rep 683
Posts 
Or engineer. Had to take all the math classes a math major would minus the little programming courses they have to take. Debated getting a math minor, but figured it'd be useless as an engineer.

Appreciate
0

09112013, 08:38 AM  #19  
Major
72
Rep 1,169
Posts
Drives: 13 C300 Sport
Join Date: Aug 2007
Location: BOS now..formerly SoCal

Quote:
same here
__________________
Retired: 08E92xZSPxSTYLE230xSADDLExPDCxPADDLExCOMFORT/JB3 tune
Current: 13 w204/white/sport/dynamicaamg interior/multimedia/rear roof spoiler/trunk spoiler/heated seats A fisherman always sees another fisherman from afar 

Appreciate
0

09112013, 09:22 AM  #20  
Captain
9
Rep 729
Posts 
I am a fucking engineer and can't remember how to solve that shit
__________________
Quote:


Appreciate
0

09112013, 10:35 AM  #21 
Lieutenant Colonel
17
Rep 1,621
Posts
Drives: 2007 Z4M Coupe
Join Date: Apr 2010
Location: NJ

Engineer reporting in. I took up to Calc 4 in college and I can tell you unless you become a Calc professor, no need to remember any of it.
OP, wish I could help but that part of my brain is in retirement.
__________________
Gruppe M CAI / Euro Headers / Rogue Engineering Xpipe / RE Diablo Exhaust 
Appreciate
0

09112013, 10:50 AM  #22  
Captain
8
Rep 672
Posts 
Quote:
I do not miss one moment of it. Welcome to hell OP... welcome to hell. 

Appreciate
0

Bookmarks 
Thread Tools  Search this Thread 

