Eris13696
Badges: 12
Rep:
?
#1
Report Thread starter 1 month ago
#1
Hello everyone, I hope you’re having a great day.

I wanted to ask about infinity. When do I know if the infinity will make the integral =0? Because all I understand if the number is trying to approach a 0 then we can make it a 0. I hope someone can clear my confusion about it. Like in this question how is it approaching 0?
Attached files
Last edited by Eris13696; 1 month ago
1
reply
Shaqiloheal
Badges: 9
Rep:
?
#2
Report 1 month ago
#2
(Original post by Eris13696)
Hello everyone, I hope you’re having a great day.

I wanted to ask about infinity. When do I know if the infinity will make the integral =0? Because all I understand if the number is trying to approach a 0 then we can make it a 0. I hope someone can clear my confusion about it. Like in this question how is it approaching 0?
By applying the common limit:

u -> -infinity (e^u) = 0

This is proven by applying the limit property

Lim_x -> -infinity (2x+3)
a=2 n=1
= -infinity

Therefore 1/2 * 0 = 0

The limit as x approaches zero would be negative infinity, since the graph goes down forever as you approach zero from either side: As a general rule, when you are taking a limit and the denominator equals zero, the limit will go to infinity or negative infinity.

Hope this helps. Sorry I did this on my phone.

By any chance are you a pure/applied mathematics student?
1
reply
Eris13696
Badges: 12
Rep:
?
#3
Report Thread starter 1 month ago
#3
(Original post by Shaqiloheal)
By applying the common limit:

u -> -infinity (e^u) = 0

This is proven by applying the limit property

Lim_x -> -infinity (2x+3)
a=2 n=1
= -infinity

Therefore 1/2 * 0 = 0

The limit as x approaches zero would be negative infinity, since the graph goes down forever as you approach zero from either side: As a general rule, when you are taking a limit and the denominator equals zero, the limit will go to infinity or negative infinity.

Hope this helps. Sorry I did this on my phone.

By any chance are you a pure/applied mathematics student?
Thank you for your reply, unfortunately I haven’t been introduced to the limit properties or the common limit, so is there a good video that can summarize them so I can understand it. So when I see -infinity I will assume directly it’s equal to 0? yes, I’m studying pure math.
0
reply
Shaqiloheal
Badges: 9
Rep:
?
#4
Report 1 month ago
#4
(Original post by Eris13696)
Thank you for your reply, unfortunately I haven’t been introduced to the limit properties or the common limit, so is there a good video that can summarize them so I can understand it. So when I see -infinity I will assume directly it’s equal to 0? yes, I’m studying pure math.
Its much easier to explain the concept with a graph. The aysmptore of the line would be going down the negative end of the y axis to zero infinately. Thats the best way to explain it.

Nice im away to start my 1st year in Applied Mathematics at University of Abedeen. I just finished my HNC in Electrical Engineering but fell in love with mathematics. I have experience withe intergral and differential calculus through Engineering Mathematics 2 which was my final unit therefore definate intergrals are fresh in my head.

Which uni are you at?
Last edited by Shaqiloheal; 1 month ago
0
reply
Eris13696
Badges: 12
Rep:
?
#5
Report Thread starter 1 month ago
#5
(Original post by Shaqiloheal)
Its much easier to explain the concept with a graph. The aysmptore of the line would be going down the negative end of the y axis to zero infinately. Thats the best way to explain it.

Nice im away to start my 1st year in Applied Mathematics at University of Abedeen. I just finished my HNC in Electrical Engineering but fell in love with mathematics. I have experience withe intergral and differential calculus through Engineering Mathematics 2 which was my final unit therefore definate intergrals are fresh in my head.

Which uni are you at?
That’s very cool that you are pursing your love for math, it’s a very interesting but challenging field. I’m not in uni yet, I’m doing this for maths A levels in the oct/nov session. Is there a general rule for these infinity because they always confuse me, there was no topic covering them in the book, they just got introduced in integration.
0
reply
RDKGames
Badges: 20
Rep:
?
#6
Report 1 month ago
#6
(Original post by Eris13696)
Hello everyone, I hope you’re having a great day.

I wanted to ask about infinity. When do I know if the infinity will make the integral =0? Because all I understand if the number is trying to approach a 0 then we can make it a 0. I hope someone can clear my confusion about it. Like in this question how is it approaching 0?
As a tends to -infinity, the exponent 2a+3 also tends to -infinity. This should be obvious.

So then what happens to the exponential function as its argument goes to -infinity? It decays to 0.
1
reply
X

Quick Reply

Attached files
Write a reply...
Reply
new posts
Back
to top
Latest
My Feed

See more of what you like on
The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

Personalise

Are you tempted to change your firm university choice on A-level results day?

Yes, I'll try and go to a uni higher up the league tables (53)
28.96%
Yes, there is a uni that I prefer and I'll fit in better (15)
8.2%
No I am happy with my choice (101)
55.19%
I'm using Clearing when I have my exam results (14)
7.65%

Watched Threads

View All
Latest
My Feed

See more of what you like on
The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

Personalise