How can I integrate a sinusoidal current in an L-C circuit undergoing resonance?

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Homework Help Overview

The discussion revolves around integrating a sinusoidal current in an L-C circuit that is undergoing resonance. The current is expressed as I(t) = I*cos(omega*t), and participants are exploring the integration process and the implications of constants involved in the equation.

Discussion Character

  • Mathematical reasoning, Assumption checking

Approaches and Questions Raised

  • Participants are attempting to integrate the sinusoidal function and are questioning the correctness of their results. There is discussion about the nature of constants involved, particularly omega and I, and whether omega can be treated as a function of time.

Discussion Status

The conversation is ongoing, with some participants providing insights into the integration process and clarifying the roles of constants. There is a recognition of confusion regarding the integration of sinusoidal functions and the definitions of the variables involved.

Contextual Notes

Some participants express uncertainty about their understanding of high school-level mathematics, particularly integration techniques, and the definitions of constants in the context of the problem.

Ivegottheskill
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An L-C circuit will undergo resonance, with the current varying sinusoidally, where:
I(t) = I*cos(omega*t)

I keep getting stuck with an answer of I*t*sin(omega*t)

Can't find anything on the standard table of integrals that would indicate this is incorrect

:confused:
 
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How did you get the answer of I*t*sin(omega*t)
 
I*cos(omega*t)

omega's just a constant then? I'll call it a

I*cos(at)

I's a constant too, so you'll only integrat cos(at)

which should be sin(at)/a

so I*sin(omega*t)/omega?

Other possibility, since I'm not sure myself, is that you can express omega as a function of time, can't you? (2pi*frequency)and frequency is like 1/t or something. I dunno, I think the first way's right

Edit: Wait, I isn't a constant, well whatever, I'll leave this post up here for learning purposes but methinks it's rubbish
 
so I*sin(omega*t)/omega?
That looks correct. I wasn't sure what you were integrating.

omega isn't a funtion of time - it is a constant.

omega is only a funtion of time if it varies with time.
frequency isn't a function of time either, but usually, a constant value. frequency is simply the rate at which something changes wrt time. But that rate of change is constant!
 
schattenjaeger said:
Edit: Wait, I isn't a constant, well whatever, I'll leave this post up here for learning purposes but methinks it's rubbish

That I is a constant - it's the value of the current at time t = 0 (usually).
 
Thanks I'll give that a shot. Sorry for the confusion, omega was a constant (angular frequency). I'm worried about how much high school stuff I've already forgotten :eek:

I wasn't sure how to properly intergrate in that case.

I tried looking it up, but could only find the simple cases (i.e. integrate sin x = cos x)
 
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