You can graph rectangular-coordinate inequalities by replacing the =
sign with <, <=,
>
or >=
for many simple functions and relations. This feature is presently only available for Cartesian graphs.
The region that solves the inequality is hatched in with the graph color. (For <= or >= the curve is drawn as a solid line, but for < or > the curve itself is dotted to indicate a strict inequality.) In most cases, asymptotes are detected and a boundary added there as appropriate, so graphs like y < tan x
or xy > 1
are drawn correctly. In addition, the valid domain of the function being graphed is detected automatically, so y > log x
, for instance, shades only the first and fourth quadrants.
When you select the monochrome color scheme, the graphing routine alternates between \
and /
hatching to accommodate intersecting regions. Best results will be obtained when you graph no more than two overlapping inequalities on the same screen.
Single-variable inequalities consisting of expressions that are differentiable with respect to that variable (e.g. x^2 > -x
) are also supported. They are solved as a set of intervals that satisfy the inequality. Note that the inequality is only solved for the portion of the domain currently shown on screen. Thus the first and last interval shown in the point tables may be partially unspecified. This does not necessarily mean that the inequality is satisfied continuously up to negative or positive infinity, simply that the missing end of the interval (if any) falls off-screen and thus was not computed.