PolarPloting by useing Mathematica

[Psi-String]

If I want to polarplot a function, say, r=cos(t) , what instructions should I type?

I tried this before:

PolarPlot [ Cos[t] , {t, 0, 2 Pi} ]

but it just brought out the same thing!

PolarPlot [ Cos[t] , {t, 0, 2 Pi} ] ,not the graph!

Where did I went wrong??

 

[FredGarvin]

Don't put a space after PolarPlot (or anywhere else).

Your command line should read: PolarPlot[Cos[t],{t, 0, 2 Pi}]

Ref: http://documents.wolfram.com/mathematica/Add-onsLinks/StandardPackages/Graphics/Graphics.html