# To build a complex polynomial

For example I have this polynomiyal:

```
p=(z-2*I)*(z+1*I)
```

I want sage show me someting like:

```
z^2-z*(1*I)-2
```

It doesn't mind the number of roots.

add a comment

To build a complex polynomial

asked
**
2016-01-17 13:22:11 -0500
**

This post is a wiki. Anyone with karma >750 is welcome to improve it.

For example I have this polynomiyal:

```
p=(z-2*I)*(z+1*I)
```

I want sage show me someting like:

```
z^2-z*(1*I)-2
```

It doesn't mind the number of roots.

add a comment

1

Is that what you want?

```
sage: var('z')
sage: p=(z-2*I)*(z+1*I)
sage: p.expand()
z^2 - I*z + 2
```

Asked: **
2016-01-17 13:22:11 -0500
**

Seen: **56 times**

Last updated: **Jan 17 '16**

Write sage code to find the Bezout coefficients of two polynomials b(x), c(x)

Unexpected behavior of log() in complex plane

Creating an array of variables

Is there a way to get the homogeneous part of certain degree of a (multivariate) polynomial?

Explicit representation of element of ideal

Copyright Sage, 2010. Some rights reserved under creative commons license. Content on this site is licensed under a Creative Commons Attribution Share Alike 3.0 license.