The equation is an approximation: It is derived from the first term in a Taylor series. The speed of light is an approximation because it cannot be measured perfectly. C is a theoretical concept.
NOPE! Saying it doesn't make it so.
The speed of light has been measured a million times over many decades of time. The most accurate physical measurement was done in 1973 and measured a speed of 299792.4574 m/s +-0.0011 meters/sec. That's an accuracy of 1 part in 272,538,597.6363636.
Further more c is now EXACTLY 299792458 metres per second, by definition!
In no way is that an aproximate value nor is it a theoretical concept.
It makes no sense why you cannot let this go! You're wrong! You're just simply flatly completely and totally wrong? Why continue to repeat this idiotic nonsense?
I can quote as many sources as there are in existence on what the speed of light is. Why do you persist? Where's the pay off? What possible motive could there possibly be for this lunacy?
I swear it feel like I'm talking to a bunch of flat earthers!