Uncertainty in Algebraic Substitution: Is X=0?

In summary, the conversation is about a problem involving substitution and uncertainty. The individual is struggling to understand the second step and the use of symbols. It is eventually discovered that the problem was translated incorrectly and the solution uses identities to prove a limit. The conversation ends with a clarification that x does not equal pi and the ratio being undefined if x is equal to pi.
  • #1
Misr
385
0

Homework Statement



[PLAIN]http://img137.imageshack.us/img137/4242/probhr.jpg


Well ,my problem is why after substitution for the first time the result os uncertainity (0/0)

Is X=0?

and I don't understand the step no 2
 
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  • #2
What you've written doesn't make sense.
 
  • #3
so...?
 
  • #4
Misr said:
so...?

I think they mean the symbol you are writing as 'A' to be the symbol for pi.
 
  • #5
Go back and check that you accurately copied the original problem and the solution. It's pointless to try explain something that is wrong to begin with.
 
  • #6
I think they mean the symbol you are writing as 'A' to be the symbol for pi.
awww you are right.The problem was written in another language so I translated it in a wrong way...I'll try to solve it again

Thanks for all of you
 
  • #7
Ok..I'm back
so I know that sin(180-x)=sin(pi-x)

but x= pi right?
so sin(pi-x) = sin (x-pi) ?
why did we use sin(pi-x) instead ?
hope u could understand me
thanks
 
  • #8
x doesn't equal pi. But for any x, sin(x)=sin(pi-x)=(-sin(x-pi)). Look at graph of the sin function or use a sin addition formula to prove that. They are using those identities to prove the limit.
 
  • #9
x doesn't equal pi.
so why not?
isn't x-pi=0 as mentioned in the problem ?
 
  • #10
Misr said:
so why not?
isn't x-pi=0 as mentioned in the problem ?

x-pi->0. That means x approaches pi (gets closer and closer to pi). It's not equal to pi. If x=pi then you have a zero in the denominator and the ratio is undefined.
 
  • #11
oh ok thanks very much
 

FAQ: Uncertainty in Algebraic Substitution: Is X=0?

1. What is uncertainty and why is it important to solve?

Uncertainty refers to a lack of knowledge or information about a particular situation or outcome. It is important to solve because it can lead to confusion, indecision, and potential risks or negative consequences.

2. How do scientists approach solving uncertainty in their research?

Scientists use the scientific method, which involves making observations, formulating hypotheses, conducting experiments, and analyzing data to draw conclusions and reduce uncertainty. They also rely on peer review and replication of results to increase confidence in their findings.

3. Can uncertainty ever be completely eliminated?

No, uncertainty is a fundamental part of the scientific process and the nature of the world. However, through careful research and analysis, scientists can reduce uncertainty and increase our understanding of a particular phenomenon.

4. How does solving uncertainty benefit society?

Solving uncertainty through scientific research can lead to advancements in technology, medicine, and other fields that improve our quality of life. It can also help us make more informed decisions and avoid potential risks or negative consequences.

5. Is it possible to have too much certainty?

Yes, having too much certainty can lead to closed-mindedness and prevent us from considering new information or alternative perspectives. It is important to maintain a healthy level of skepticism and continue to question and evaluate our beliefs and knowledge.

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