



 
Hi Al, We had a similar question a while ago and Edward showed that the curve is a cosine. For your question the curve you need is one period of the cosine. The length of the period is the circumference of the pipe which is 200 π and the amplitude is 200/2 = 100. (You didn't tell us the units but I assume they are millimeters.) Thus the curve is
where the angle is measured in radians, not degrees. In the diagram the axes are in green. The red lines mark off one period. I printed the diagram, cut along the curve and red lines and rolled it up to form the cut off cylinder in the image at the top of this page.
I hope this helps,  


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