Hard Light Productions Forums
Off-Topic Discussion => General Discussion => Topic started by: Ashrak on October 09, 2005, 03:32:30 am
-
can any of you guys help me with the following 3 asigments please? :)
(http://img255.imageshack.us/img255/1805/mat7hv.jpg)
Cheers
-
first one's 2/3
second one's 1
third one's 0
-
yes but HOW do you solve it?
-
The third one simplified becomes 3x^2 divided by x^3 or 3/x.
-
and the -2 from top and +1 from bottom just dissapear?
-
Second could go like this:
(sqr(x+1)-sqr(x)) * 2sqr(x)
((x+1-x)/(sqr(x+1)+sqr(x))) * 2sqr(x)
(1/(sqr(x+1)+sqr(x))) * 2sqr(x)
(2sqr(x)/(sqr(x+1)+sqr(x)))
(2sqr(1)/(sqr(1+1/x)+sqr(1)))
And result is 1.
using (a+b)(a-b)=a^2-b^2
About the last one:
Those -2 and +1 really does not matter at all.
I'm not really certain about the English term, but you can always reduce all the terms by the same factor (in this case try using x^2))
(3x^2-2)/(x^3+3x^2+3x+1)
(3-2/x^2)/(x+3+3/x+1/x^2), got it?
As x approaches the infinate it doesn't matter what the other numbers are...
-
in the end of the second one why do you substitute x as 1 instead of infinity?
-
with the rule of l'hospital?
EDIT: My sister posted the above, she's around 4 years older then me (That is, 17), so she knows alot more
-
im not suposed to use l'hospitals rule on this test lol
-
There is also possibility that i have screwed up... Haven't really touched these since, well year 2000?
-
I believe that when you're talking about limits of equations like those, it's all about the powers involved above and below the fraction. So, although I don't remember exactly what my teacher said about all that last year, Bob might be right. Meh.
-
just out of curiosity, what level of math is this?
*is just now taking calculus*
now I know the stuff I have to look forward to :shaking:
-
10th grade Geometry...w00t. I opted to take AP Music Theory instead of taking Algebra II same year as Geometry. Math isn't a strong point of mine.
...wtf is lim anyway? Just curious.
-
(i believe) a limit is the value of y as the graph of x approaches y.
-
I feel kinda dumb now. I knew what limits were, I just didn't connect that with the abbreviation.:nervous:
-
Originally posted by Ashrak
im not suposed to use l'hospitals rule on this test lol
That's always what pissed me off about math:
Oh no! You can't factor it by using the quadratic equation!
Oh no! You're not allowed to use that theorem a few chapters ahead to solve the equation!
What the hell was the point of those people to develop new theorems and such if we're not allowed to use them?
-
Originally posted by Ace
That's always what pissed me off about math:
Oh no! You can't factor it by using the quadratic equation!
Oh no! You're not allowed to use that theorem a few chapters ahead to solve the equation!
What the hell was the point of those people to develop new theorems and such if we're not allowed to use them?
amen, brother
-
That's always what pissed me off about math:
Oh no! You can't factor it by using the quadratic equation!
Oh no! You're not allowed to use that theorem a few chapters ahead to solve the equation!
What the hell was the point of those people to develop new theorems and such if we're not allowed to use them?
I used to hate that so much. I still ran into this nonsense on a test last year, but at least the theorem you were not supposed to use was something from another class. Although I had another professor who said you could use whatever you know on anything in his class, which was good to see.
-
Uhh, which math class are you in? I want to know how long unitl i die from that!
(I barely get what they are asking)
(Eighth grade geometry does things to you... It's way too easy, especially when you look at the prerequisites)
-
huh, me? The bad test problem was in a number theory class and the good professor was for a graduate complex analysis class. Although you probably won't need to bother with these things unless you will be doing a math or possibly physics degree.
-
Oh. Cool.
-
Originally posted by Ashrak
in the end of the second one why do you substitute x as 1 instead of infinity?
Sorry for this coming so late but i really thought you knew (as you seem to know at least the basics of the limits) that you can not divide infinite by infinite (or zero by zero) unless you know the tricks to make it work, like classic lim(x->0) sin x / x (it is "0/0" case) which equals 1. You can not have the infinate existing in both numerator and the denominator as you can not divide undefined value by another undefined value (as infinite is by defination an undefined value).
So in the calculation i simply builded the fraction or in other words multiplied both the numerator and the denominator by the same value, in this case the value was Sqr(1/x) (i hope these are the English terms). So i got following: Sqr(x)Sqr(1/x) =Sqr(x/x) =Sqr(1) =1 and Sqr(x+1)Sqr(1/x) =Sqr(x/x+1/x) =Sqr(1+1/x).