solid of revolution

tpgettys shared this question 2 years ago
Answered

I would like to first show the area under the graph of y=sqrt(x) between 1 and 4 (y>0), then show the solid of revolution about the x-axis, preferably using a slider for the angle of revolution. How might that be done?

Comments (2)

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Define a function f(x)= If(1 ≤ x ≤ 4, sqrt(x)) a slider 'angle'.

Then you show the solid of revolution with the command Surface(f, angle, xAxis)

You could show just the upper (positive) part while limiting the range of the slider


chris

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I use a trick to show the rotating trapezoid ;)

First, create the trapezoid, say trap:

Surface(t, u f(t), 0, t, 1, 4, u, 0, 1)
where 1, 4 are the interval bounds, then I rotate it:

Rotate(trap, α, xAxis)

and activate the trace for it.

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