What is i equal to?

Am i or am i not \sqrt{-1}? Khan Academy say I am, www.jamestanton.com says I’m not. It is really very tempting to deduce that because i^2 = -1, i = \sqrt{-1}. Many have fallen victim to this.


This post is part of my series of posts about common misconceptions in mathematics.

  1. Mistakes vs Misconceptions
  2. Top ten errors in algebra
  3. Math just got different with integers

Good mathematics teaching practice exposes misconceptions, not hide them.

If this post is of help, share it with your co-teachers.


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