Still struggling with trying to remember math skills I had many decades ago and haven't used since. At the suggestion of a mentor, I've paused working my way through the beginnings of the Horowitz/Hill AoE book and have moved into Stuart Hoenig's book, second edition. I can't get past one step between page 19 and 20, where he's discussing rudimentary determination of resistance and capacitance in terms of reactance for a filter. He describes the voltage across the capacitor, Vc, as =IXc, which makes sense, referring to Ohm's Law V=IR, with the reactance of the capacitor, Xc, subbing for R. So far, so good.
The next step subs V/(Xr+Xc) for I in that formula, which I also understand, yielding Vc= VXc/(Xr+Xc). OK so far.
He then writes that "Rewriting the above and recalling that Xc=1/(2πϝC), we obtain ---
Vc/V = 1/(2πϝRC+1) "
I know this is REALLY basic stuff, but I can't make the leap and figure out how he got there. I can get to ..
Vc/V=Xc/(Xr+Xc)
and then plug in for Xc ...
Vc/V=(1/(2πϝC))/(Xr+1/(2πϝC))
yielding Vc/V=Xr/(2πϝC) + (1/(2πϝC))^2 --- but then I'm done and I have a headache... and I'm not sure I'm even going down the right path. I also don't understand how R, the resistance of the resistor, reappears in his formula at the top of p.20, "Vc/V = 1/(2πϝRC+1)"
As I said, I know this has to be incredibly basic to almost everyone here, but it's been a VERY long time since I did anything like this... can't believe I made it as far as Calc BC back in the late 70s, and can't remember this stuff. I'd be very grateful for any help.
Here's picture of the excerpts from his book that has me baffled... first the circuit, then then the starting formula, and then the one I can't get to....