I am familiar with complex nos. I know about their algebric manipulations, for example. But I could not understand the notion of ´iota´. I know that complex numbers are extremely essential for solving the equation involving cube roots or higher or negative square root of a number. I am also aware of their use in Quantum Physics and I, therefore, know about the importance of ´iota´. But I am unable to understand their working. It appears to me that we have assume a greek letter for say finding the negative squareroot of number and thus everything is ok with it. If, for example, this is the way of finding the solutions then why don´t we take any real no divided by zero as equal to another Greek letter, say, omega. Secondly, I am confused with the graphical representation of the complex numbers. We represent them using Argand Diagram and whenever I compare the Argand Diagram to the two dimensional real plane I donot find any difference. What is this nonsense? Finally, Do we have Argand diagram in more than two dimension? I am very irritated with these questions please help me out.