I just joined here. I've been looking for a place to get some help on some things. I'm trying to get my GROL test done and there are some things on element 3 that I don't know how to do. I can memorize the answers but I would like to actually know how to get that answer. One problem is with power factors. example: What does the power factor equal in an R-L circuit having a 60 degree phase angle between the voltage and the current? The answer is 0.5. The other section I was having problems with was the impedance networks. Example: What is the impedance of a network composed of a 100 picofarad capacitor in parallel with a 4000 ohm resistor, at 500 Khz? specify your answer in polar coordinates. The answer is 2490 ohms,/-51.5 degrees. No clue how to get that though. Any help with this would be greatly appreciated. Thanks!