Question

integers & complex no. both can be represented by Z why so?

Answer 1

Any number can be represented by any symbol, so long as the context makes it clear what set that number belongs to. It's a matter of convention that mathematicians set aside certain letters to represent numbers from various sets.

z is typically the representation of a number in the complex field.
x is typically the representation of a number in the real field.
q is typically the representation of a number in the rational field.
n is typically the representation of a number in the integral field.

I think what may have confused you is seeing the following:\[\mathbb{Z}\]versus\[z\]The first "Z" is the letter used for the integral field (the set of all integers). The second 'z' is the typical representation of a complex number.

Hope this helps.

Answer 2

thx