What does an i stand for in an algebraic equation?

Answer 1

The i is for "imaginary". Taking the square root of a negative number will return an imaginary number. Imagines aren't particularly helpful, but do find use in certain fields of study, like electrical engine ring. For example, an inductor or capacitor neither produces nor consumes any real power, but do supply or absorb a reactive power, which is represented by a complex (imaginary number). Therefore, "i" is analytical useful, but not physically useful, if you know what I mean.