Solid Of Revolution

Hello! I have a problem that is hard to solve, I need to generate the image of a solid of revolution from the function y = ((x ^ 4) / 8) + (1 / (4 * (x ^ 2)));

I searched several websites, books and tutorials but found nothing to help me how to rotate this function. I've tried using the command cylinder, but neither worked.

What I got so far was this:

clear
close all
clc

x=sym('x');

y=((x^4)/8)+(1/(4*(x^2)));

[X,Y,Z]=cylinder(y);

ezsurf(X,Y,Z); title('Solid of Revolution'); xlabel('X'), ylabel('Z'), zlabel('Y');

Could anyone help me?

Thanks!

Answer 1

[Walter Roberson]

You aren't going to be able to plot an infinitely wide surface, which is what you are implicitly asking to do by allowing 0 to be included in the range for x (the default domain is -120 to +120 for x and y). The surface tends toward infinity as x tends towards 0 and as x tends towards infinity. Unless you cut a fairly narrow band, you are going to have a mess. And if you do cut a specific band, you can use specific x values to generate the solid rather than trying to get cylinder() to work with symbolics.