the name seems to be an unfortunate choice that stems from their historical usage as “a means to an end”. i.e, they were first used as part of a method to find some solutions to cubic equations. this method would require algebraic manipulations of complex numbers, but the ultimate goal was to discover a real root. the complex roots would be discarded once a real root was found (if it existed).
the wikipedia article attributes the name to Descartes:
… sometimes only imaginary, that is one can imagine as many as I said in each equation, but sometimes there exists no quantity that matches that which we imagine.
which i think helps to highlight how skeptical the people at that time were about the existence of the “imaginary” numbers.
the name seems to be an unfortunate choice that stems from their historical usage as “a means to an end”. i.e, they were first used as part of a method to find some solutions to cubic equations. this method would require algebraic manipulations of complex numbers, but the ultimate goal was to discover a real root. the complex roots would be discarded once a real root was found (if it existed).
the wikipedia article attributes the name to Descartes:
which i think helps to highlight how skeptical the people at that time were about the existence of the “imaginary” numbers.
source: memories of my first complex analysis class, and https://en.wikipedia.org/wiki/Complex_number#History
i’d strongly recommend reading the history section of that wikipedia page to anyone interested in the topic, it has some pretty fun history