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August 11th, 2011, 04:11 PM   #1
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Confusion.

So, we start with:



Then we get:

by multiplying the equation by

Wolfram Alpha does not agree with this:

http://www.wolframalpha.com/input/?i=Z%3D%5Cfrac{%5Cfrac{1}{i%5Comega+C}*%28R%2Bi%5Comega+L%29}{R% 2Bi%5Comega+L%2B%5Cfrac{1}{i+%5Comega+C}}

Why?

Same result if I approach it a different way:

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August 11th, 2011, 04:18 PM   #2
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Re: Confusion.

[color=#000000]It seems like a physics formula, what is the intensity? Wolframalpha may interpret it as the complex .[/color]
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August 11th, 2011, 04:21 PM   #3
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Re: Confusion.

Quote:
Originally Posted by ZardoZ
[color=#000000]It seems like a physics formula, what is the intensity? Wolframalpha may interpret it as the complex .[/color]
Oops. Should've noted that is the imaginary unit.
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August 11th, 2011, 06:30 PM   #4
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Re: Confusion.

Intriguing. Seems it agrees with me now:

http://www.wolframalpha.com/input/?i=%28%5Cfrac{R%2Bi*w*L}{i*w*C}%29%2F%28%5Cfrac{R*i*w*C%2Bi^2*w ^2*L*C%2B1}{i*w*C}%29

Wolfram must have an issue with complex fractions?
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August 12th, 2011, 08:21 AM   #5
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Re: Confusion.

Quote:
Originally Posted by ZardoZ
[color=#000000]It seems like a physics formula, what is the intensity? Wolframalpha may interpret it as the complex .[/color]
You are right it's an RCL circuit. isn't an imaginary number. It's already in the simplest form after truncating a long series. I nonplused what Ms Pi is trying to achieve.
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August 12th, 2011, 08:58 AM   #6
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Re: Confusion.

Quote:
Originally Posted by Math Dreamer
Quote:
Originally Posted by ZardoZ
[color=#000000]It seems like a physics formula, what is the intensity? Wolframalpha may interpret it as the complex .[/color]
You are right it's an RCL circuit. isn't an imaginary number. It's already in the simplest form after truncating a long series. I nonplused what Ms Pi is trying to achieve.
The book I took this from states that it's an imaginary number and the actual problem set is in the chapter on Complex Numbers. . .
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August 12th, 2011, 09:14 AM   #7
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Re: Confusion.

[color=#000000]I think that if the i denotes the imaginary , then Z is the impedance of an AC circuit, since electric flow changes direction periodically, so if this formula describes an AC circuit it is correct. I haven't studied physics since high-school though so I am not sure! As far as I can remember R stands for resistance and C for capacity. [/color]
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August 12th, 2011, 09:36 AM   #8
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Re: Confusion.

Quote:
Originally Posted by ZardoZ
[color=#000000]I think that if the i denotes the imaginary , then Z is the impedance of an AC circuit, since electric flow changes direction periodically, so if this formula describes an AC circuit it is correct. I haven't studied physics since high-school though so I am not sure! As far as I can remember R stands for resistance and C for capacity. [/color]
Thank you. That's what I was asking about. I think that Wolfram Alpha has an issue with complicated fractions--maybe it renders them wrong?
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August 12th, 2011, 10:04 AM   #9
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Re: Confusion.

Quote:
Originally Posted by ZardoZ
[color=#000000]I think that if the i denotes the imaginary , then Z is the impedance of an AC circuit, since electric flow changes direction periodically, so if this formula describes an AC circuit it is correct. I haven't studied physics since high-school though so I am not sure! As far as I can remember R stands for resistance and C for capacity. [/color]
R is the resistance, L the induction, C the capacitance, and i the current. I found it in library from a physics book, then it leads to a WWII HF radio. Radio at it's crudest stage. It got my friend fired up. We will have a trip to a junk yard for parts. The junk yard is our Walmart.
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August 12th, 2011, 12:07 PM   #10
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Re: Confusion.

Quote:
Originally Posted by ZardoZ
[color=#000000]???????? ????????, ???? ??????? ???????? (????? ???????? ?????????? ???? ???????????, ????? ???????? ???????????? ????????????, ???????? ??? ????? ?????????? ????? ?????? ??????? ????????), ???????? ??????????, ???? ????? ????????? ???????? ????? ????? ??? ????????? ????????? ??????, ????????? ?????????? ???????? ??????? ?????????? ?????. [/color]
This is what I see there, I know nothing of physics

I searched for "impedance" and the definition was the same of resistance, but it says the resistance is the real part of the impedance.. how come is a fraction of two real numbers (potential difference and current) a nonreal number in any sense? Physics is just so unearthly sometimes..
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