Identity Elements

Identity elements exist for Addition and Multiplication.

The identity element for Addition is zero.

$a + 0 = 0 + a = a$

The Identity Element for Multiplication is unity, more commonly called “One”.

$a * 1 = 1 * a = a$

Sometimes the letter ‘e’ is used to symbolize an identity element and * is used, not as multiplication, but rather, a generic binary operation.

$a*e=e*a=1$

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