PolarPlot[{2 Sin[3 x], 1 + Cos^2[3 x]^2}, {x, 0, 2 [Pi]}]
It works when you input: PolarPlot[{2 Sin[3 x], 1 + (Cos[3 x])^2}, {x, 0, 2 Pi}]
the two equations i wanted were r= 2Sin(3x) and r= 1+Cos^2(3x)
You probably need the following syntax. I assumed you wanted cos^2((3x)^2))
cos^2((3x)^2))
PolarPlot[{2 Sin[3 x], 1 + Cos[(3 x)^2]^2(*cos^2 must be (Cos[])^2*)}, {x, 0, 2 Pi(*without the [] around Pi*)}]
