Which point on Figure E5-1 best represents the impedance of a series circuit consisting of a 400-ohm resistor and a 38-picofarad capacitor at 14 MHz?

توضیح
The capacitor's reactance at 14 MHz works out to about 299 Ω, and being capacitive it is negative, so the impedance is roughly 400 − j299 ohms. On Figure E5-1 that is 400 to the right and 300 below the horizontal axis, which is Point 4; Point 2 would be positive imaginary reactance, Point 6 a pure resistance, and Point 5 a negative resistance.