## Description

There are some inequalities where the relationship between $x$ and $y$ cannot be expressed as a function, such as

(1)To plot these, we can use the `region_plot` command.

## Sage Cell

#### Code

```
y = var('y')
region_plot(cos(x^2 + y^2) <= 0, (x, -5, 5), (y, -5, 5))
```

## Options

#### Style Options

We can change the look of the graph by setting the `bordercol` (color of the border), `incol` (color of the fill) and `alpha` (transparency of the fill).

#### Code

```
y = var('y')
region_plot(cos(x^2 + y^2) <= 0, (x, -5, 5), (y, -5, 5), bordercol='black', incol='yellow', alpha=2/3)
```

## Tags

Primary Tags:

Secondary Tags:

A list of possible tags can be found at The WeBWorK Open Problem Library. For linear algebra tags see the Curated Courses Project.

## Related Cells

Any related cells go here. Provide a link to the page containing the information about the cell.

## Attribute

Permalink:

Author: Gregory V. Bard. *Sage for Undergraduates.* American Mathematical Society, Providence, RI, 2015. Available at http://www.gregorybard.com/Sage.html.

Date: 03 Mar 2019 19:16

Submitted by: Zane Corbiere