var ('x, y, z') implicit_plot3d (abs (x) + abs (y) + abs (z) - 1, (x, -1,1), (y, -1,1), (z, -1,1), color = 'aquamarine ')

1 | initial version |

var ('x, y, z') implicit_plot3d (abs (x) + abs (y) + abs (z) - 1, (x, -1,1), (y, -1,1), (z, -1,1), color = 'aquamarine ')

var ('x, y, ~~z')
~~z') # with SageMath 7.3

implicit_plot3d (abs (x) + abs (y) + abs (z) - 1, (x, -1,1), (y, -1,1), (z, -1,1), color = 'aquamarine ')

~~var ('x, y, z') # with SageMath 7.3~~We know that $|x| + |y| - 1 = 0$ is the equation of a square having its vertices on the axes.

~~implicit_plot3d (abs (x) ~~I asked to represent the equation $|x| + ~~abs (y) ~~|y| + ~~abs (z) ~~|z| - ~~1, ~~1 - 0$, believing to obtain a cube in space.

But I obtain an octahedron. Why? And how do you get a cube?

```
# with SageMath 7.3
var('x, y, z')
f = abs(x) + abs(y) + abs(z) - 1
implicit_plot3d(f, (x,
```~~-1,1), ~~-1, 1), (y, ~~-1,1), ~~-1, 1), (z, ~~-1,1), color = 'aquamarine ')~~-1, 1), color='aquamarine ')

We know that $|x| + |y| - 1 = 0$ is the equation of a square having its vertices on the axes.

I asked to represent the equation $|x| + |y| + |z| - 1 - 0$, believing to obtain a cube in space.

But I obtain an octahedron. Why? And how do you get a cube?

```
# with SageMath 7.3
var('x, y, z')
f = abs(x) + abs(y) + abs(z) - 1
implicit_plot3d(f, (x, -1, 1), (y, -1, 1), (z, -1, 1), color='aquamarine ')
```

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