# Homework Help: Period of a Sine Function

1. Jun 18, 2017

### jdawg

1. The problem statement, all variables and given/known data
Given the wave form, determine the period, frequency, peak amplitude, peak to peak amplitude, voltage offset, phase angle, signal equation, rms voltage.

2. Relevant equations

3. The attempt at a solution

Hi! So the main issue I'm having with this problem is reading the values I need from this graph. I uploaded a picture of the wave and a helpful diagram of a sine wave that define what all the values I need are.

I know that the period is the distance between the peaks of the wave. I've seen some people divide the number of waves in the graph by the amount of time on the x axis of the graph. So for this case T=7/(50x10-6 = 7.143, which by eye-balling it it seems to be close.

For the peak amplitude, I think it is 0.5.

The peak to peak amplitude, I think it is 0.6

The voltage offset, I don't know how to find. Is there some sort of formula I'm missing?

I don't know how to find the phase angle.

The signal equation and rms voltage should be easy to find after I have all the other values.

Thank you for any help.

#### Attached Files:

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• ###### wave_def.PNG
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2. Jun 19, 2017

### cnh1995

No.
See the waveform carefully. What are the peak and valley points on the waveform?

3. Jun 19, 2017

### Staff: Mentor

The first step is to write down the general form of the equation you are trying to fit to the data. This is missing from your Relevant Equations.

4. Jun 20, 2017

### collinsmark

Actually, using the terminology of the OP's second attachment, that was correct; the peak amplitude is 0.5 V. "Peak amplitude" here is not to be confused with "signal amplitude."

It is possible to quantify this with a formula, but again, for this exercise you can eyeball it. [Edit: it will be somewhere between 0 and 360o if you represent it in degrees, or it will be between 0 and $2 \pi$ if you represent it in units of radians. Either way, you should be able to eyeball it for this exercise.]