## Description

Here we will graph the inequality

(1)Sage doesn't have a specific function to plot an inequality, so instead we will be plotting $y = 1 - x^2$ and shading all points that violate the inequality. To shade, we will set the `fill`, `fillcolor` and `fillalpha` parameters. `fill` fills from the y-value specified to the curve, `fillcolor` sets the color being used to fill and `fillalpha` sets how transparent the fill will be. We will also set `ymin` and `ymax`, otherwise Sage will plot from y = 10 to the local minima.

## Sage Cell

#### Code

`plot(1 - x^2, (x, -2, 2), gridlines='minor', ymin=-2, ymax=2, fill=10, fillcolor='yellow', fillalpha=2/3)`

## Options

#### Filling under the curve

We can fill under the curve by setting `fill` to a y-value below the curve instead of above. We will use `-10` instead of `10`.

#### Code

`plot(1 - x^2, (x, -2, 2), gridlines='minor', ymin=-2, ymax=2, fill=-10, fillcolor='yellow', fillalpha=2/3)`

## Tags

Primary Tags: Plotting: Two-dimensional plots

Secondary Tags: Two-dimensional plots: Plotting Inequalities

## Related Cells

- Plotting a Circle
- Plotting a Polygon
- Plotting an Implicit Function
- Two-Dimensional Plots
- Parametric Plots
- Line Plots
- Plotting Two-Dimensional Vector Fields
- Multiple Plots on the Same Graph
- Controlling the Viewing Window of a Plot
- Plotting Functions with Asymptotes
- Multiple Annotation Techniques for Graphing
- Occasional Issues in Polar Plotting.
- Constructing Contour Plots in Sage
- Plotting Systems of Linear Inequalities
- Plotting Nonlinear Inequalities in Sage
- Making log-log Plots in Sage

## Attribute

Permalink:

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

Date: 02 Mar 2019 21:20

Submitted by: Zane Corbiere