The above graphic was created using the Desmos Chrome Web App. Input your functions and it will draw the graph for you. Very nice to use and intuitive etc.
Currently, I'm testing out the Chrome Apps that can do useful things with Maths. Also, trying to test out some of the Mathematics software available in the Linux ecosystem. There is so much Maths software in the Ubuntu repositories!
Desmos seems to be purely online but there is another graphing package which is available as a web app and as a full Linux desktop package - Geogebra.
Geogebra will also help you to draw perpendicular bisectors and regular polygons along with functions too.
The graphic above was made in Geogebra - good fun and also intuitive.