Inequalities

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GeoGebra supports inequalities in one or two variables. There are no limitations for inequalities to appear in Algebra View, but only specific inequalities can be drawn in Graphics View:

  • polynomial inequalities in one variable, e.g. x^3 > x + 1 or y^2>y,
  • quadratic inequalities in two variables, e.g. x^2 + y^2 + x*y ≤ 4,
  • inequalities linear in one variable, e.g. 2x > sin(y) or y < sqrt(x).

For inequality sign you can use <, >, ≤, ≥. The Symbols <= and => also valid. Conjunction and disjunction are also supported for inequalities, e.g. (x>y)&&(x+y<3) can be drawn.

In order to show the solution of an inequality as one or more intervals on the x axis, select the Show on x-axis option in the Style tab of the Properties dialog of the inequality .

Inequalities are similar to functions, you can test whether x and y satisfy inequality a by typing a(x,y) in the Input Bar, also when A is a point, syntax a(A) is valid. A point can be restricted to the region given by inequality using PointIn Command. For inequality b in one variable, e.g. in x, Point[b] yields a point restricted to the part of x-axis which satisfies inequality b.

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