i know something about phasor diagrams but ive never read anything about a serie parallel duo. Can i just imagine C on the +j axes and R2 on the -x axes and r1 on the +x axes and then use simple math?

 

Um... sort of.

You can convert capacitor into its complex form: \(\frac{1}{jwC}=\frac{-j}{wC}=-\frac{1}{wC}j\)
So now capacitor is sort of "resistor" that depends on frequency w.
Since you now have two resistors in parallel, you can find their equivalent resistance, it will be complex quantity, and you can map this complex quantity, Real part goes on x axis, imaginary part goes on the y axis.

 

i do understand that but the complex impedance will be (((1/sC)*R2)/((1/sC)+R2)) im not sure how to draw that.

 

I guess i got the answer maybe somebody cares to check.
I choose R1 to be 1k
I rewrite the formula above to R2/(jwR2C+1)
i calculate the complex vanlues of z2 which turns out to be 1j+ 1.73
R2/(jwR2C+1) = 1j+ 1.73
i rewrite to j/R2 + 1,73/R2 = jwR2C + 1
i rewrite to jwc + 1/R2 = j/R2^2 + 1/73/R2^2
1/R2 must be equal to 1.73/R2^2 so r2 = 1.73
plug R2 in formula above c = 5e^-6