# 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: **57 times**

Last updated: **Jan 17 '16**

ode_solver : unable to convert to float

complex conjugate of a variable

Power of a polynomial mod (n, X^r - 1)

polynomials rings over transcendental field extensions

Computations with complex algebraic numbers?

Extract coefficients of polynomials

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.