How Do I Combine Capacitor and Inductor Impedances in Parallel?

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swooshfactory
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Homework Statement



How do I combine these into an equivalent impedence? I'm dealing with complex impedence, but I'm not sure how to make them into an equivalent impedence.

Homework Equations





The Attempt at a Solution



I guess Zeq= 1/[(1/Zc)+(1/ZL)].
Is this right?
 
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Or do I replace the capacitor by an open circuit and inductor by a short?
 
swooshfactory said:
I guess Zeq= 1/[(1/Zc)+(1/ZL)].
Is this right?

It looks pretty good to me, however I'd like to clarify a little terminology.

Z represents a complex value called impedance with both real and imaginary parts. Often however it is given as a single number which represents just the magnitude without the angle. As magnitude it is always positive.

Zc & ZL aren't correct because those values are always imaginary with no real part. Instead, the term X is used and it's called reactance.

Capacitive reactance (Xc) is always negative and Inductive reactance (XL) is always positive.

With no real parts the formula would be Xeq = 1/[(1/Xc) + (1/XL)].