How to plot sine wave and generate table

[bungouk]

Hi All,

Could someone tell me how to plot the graph and generate the table for y = 9 sin (Ɵ - 15) over 360 degree.

The coordinates need to be a 15 degree intervals


regards

Bungouk

 

[tkhunny]

Well, you could start with 0º, then move to 15º, and then on to 30º and so forth to 360º. You would have accomplished your task.

This might help: http://web.gccaz.edu/~jgutier5/Tables/The Unit Circle Table Of Values.pdf

 

[Deleted member 4993]

Hi All,

Could someone tell me how to plot the graph and generate the table for y = 9 sin (Ɵ - 15) over 360 degree.

The coordinates need to be a 15 degree intervals


regards

Bungouk

If you have a spreadsheet program (e.g. open office) - it will be fairly simple.

 

[bungouk]

does the 9 represent the amplitude, what do i do with (Ɵ - 15) part

 

[Deleted member 4993]

Yes 9 is the amplitude and '15' in this case is the phase angle. So for Θ = 35° → y = 9 * sin(35-15) = 9*sin(20°)

 

[dsk2]

Make a table as below. Use your calculator to find y. 'x' is same as 'theta'. Make sure you are working in degrees if you are using your calculator

x degrees	y=9*sin(x-15
15	9*sin(15-15)
30	9*sin(30-15)
45	9*sin(45-15)
60	9*sin(60-15)
75	9*sin(75-15)
90	9*sin(90-15)
105	9*sin(105-15)
120	9*sin(120-15)
:
:
315	9*sin(315-15)
330	9*sin(330-15)
345	9*sin(345-15)
360	9*sin(360-15)
375	9*sin(375-15)

This was already explained by the other contributors.

I would plot for a period of 360 degrees starting 15 degrees and ending at 375 degrees for the [15,375] interval in degrees for theta or x. Thus you would get a complete cycle or wave or period of values corresponding to 'y'.

Here is the fun part.
Go to www.google.com and type plot(9*sin(x-15)) in the search bar to verify your answer. Note that the plot has the 'x' or 'theta' values in radians. Remember that 180 degrees = 'pi' radians for converting from radians to degrees or vice versa.

Goodluck bungouk

Cheers,
Sai.