RC Circuit, what does it imply when resistance = capacitive reactance (R=Xc)?

[mattpd1]

Homework Statement

I am trying to complete a lab about RC circuits. I was told to make a graph of both the high-pass and the low-pass filter (frequency vs. Vin/Vout). Then I was asked this question:

"Explain why the two lines on your graph should always cross at the frequency where XC =
R. Find this frequency from your component values and compare it to your graph. What
should Vout/Vin equal for each filter at that point?"

Homework Equations

I know of two equations that contain both Xc and R:

tan(phase) = -Xc / R

and

Z= sqrt(Xc^2 + R^2)

The Attempt at a Solution

I assume I am to use one of those equations to solve the problem, but I am confused as to where to start. Can you help?

 

[gneill]

Look at the circuits of your two filters in terms of them being voltage dividers.

When the magnitude of the impedances of the resistor and capacitor are the same, what is the relationship between Vout and Vin?

 

[cupid.callin]

Z= sqrt(Xc^2 + R^2)

i guess its: Z = \sqrt{\frac{1}{(wC)^2} + R^2}