1. The problem statement, all variables and given/known data Calculate the J notation impedance of the network We have an inductor in series with a resistor and both in parallel with a capacitor. 2. Relevant equations 3. The attempt at a solution i believe it is true that if I was to say: if I have an inductor in parallel with a capacitor then: Product/Sum = XL*-XC/XL-XC This would then go like (XL*-XC)(XL+XC) / (XL-XC)(XL+XC) because of complex conjugate. If this then was as above in the original setup: We have an inductor in series with a resistor and both in parallel with a capacitor. then could you say: (R+JXL)*(-JXC) / (R+JXL-JXC) or (R+J(XL-XC)) Could I then say by complex conjugate: ((R+JXL)*(-JXC)) (R-J(XL-XC)) / (R+J(XL-XC)) (R-J(XL-XC)) Thanks for any help in advance, it is much appreciated.