+ Encuentra las raíces de la ecuación x ^ 3-21x + 20 = 0

Commands:
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h1(x):= x^2-2*x+3;

h2(x):= cos(2*x);

h3(x):= sin(1/x);

h4(x,y):=x^2+y^2;

h5(x,y):=x^2-y^2+2*x*y^2+1;

plot2d (h1(x), [x, -10, 12]);

plot2d (h2(x), [x, -10, 10]);

plot2d (h3(x), [x, -10, 10]);

plot3d (h4(x,y), [x, 0, 10], [y ,0 ,10], [palette, false], [color, magenta, blue]);             

plot3d (h5(x,y), [x, 0, 10], [y ,0 ,10]);

Solution:
=========
See link

- Exercise3.wxm

h1(x) y h2(x):
	- exercise3-h1 h2.PNG

h3(x):
	- exercise3-h3.PNG

h4(x) y h5(x):
	- exercise3-h4 h5.PNG


Link to solution:
=================
http://maxima-online.org/?inc=r-1989390068