I have no need to justify myself to you..... The only time you have answered a question is to do a cut and paste. And, in the grand scheme of things, neither one of us is designing electronic circuits..... ergo, the math that either one of us needs doesn't extend to your futile cut and paste attempt, anyway.
Let's go down through your (many) mistakes..... you state that a DC circuit can have no impedance when an impedance is something that will limit current flow - by your statement, are we to assume that resistors don't work in a DC circuit? Obviously, untrue.
You state a DC circuit has no frequency.... in the modern automobile, there are many sensors that deliver information based on a DC frequency - MAF sensors, MAP sensors, hall effect switches.... if any of these have never used frequency as information, what do they use? The same smoke you're blowing out your ass?
You can't even offer decent help or instruction to a neophyte regarding a brake lamp circuit. Folks come here looking for help... not some useless little drool spot from a buffoon that can't answer a straight question.
BTW... if you had made it as far as 3rd year, you would remember them talking about the effects of reactance is a coiled conductor... the reason a coil wont spark when the circuit is "made" but it will when the circuit is opened....
Anyone's greatest fear is that some innocent person will listen to some of your turgid little comments and either cause themselves injury or add needless costs to their problems.
And don't worry... be a long time before our shop would consider hiring someone as low on the food chain as you...