Thread: graphing inequalities

please help!
how do you graph xy<12?
i can't find any examples in my book .
thank you!

I suppose you could do this:
Transform xy<12 to y<12/x.
Sketch the graph y = 12/x, a hyperbola if I am correct.
Change your curves to dotted boundaries.
Select some test points to find regions where xy<12.
Shade the areas for which xy<12.

I think you will have a two-dimensional graph at the end.

Bye.

Originally Posted by jmmsan

please help!
how do you graph xy<12?
i can't find any examples in my book .
thank you!

Isolate y in the inequality to get



Now we want to graph

This hyperbola divides the xp plane into 3 parts. We need to check a values from each one to find where to shade.

when we check the origin (0,0) in the orginial we get This is true

So we shade the part inbetween the two hyperbola's see the attached graph.

Good luck.