Graphing inequalities with two variables

### 18.4.1 Graphing inequalities with two variables

The plotinequation or inequationplot command plots the region of the plane where given inequalities hold.

- plotinequation takes two arguments:
  - ineqs, a list of inequalities in two variables.
  - vars, a list of variables var or variables var=a..b with their ranges of values. Note that if the ranges are not specified, Xcas takes the default values of X-,X+,Y-,Y+ defined in the general graphic configuration (Cfg ▸ Graphic configuration, see Section 2.5.8).
- plotinequation(ineqs,vars) draws the points of the plane whose coordinates satisfy the inequalities ineqs.

#### Examples

plotinequation(x^2-y^2<3,[x=-2..2,y=-2..2],xstep=0.1,ystep=0.1)

plotinequation([x+y>3,x^2<y],[x-2..2,y=-1..10],xstep=0.2,ystep=0.2)