Exercise · ZW-IDENTITY-ELEMENT-002 · ★☆☆ Basic
In a group, the identity element is...
Choose one option.
Show answer
- A. Unique
Explanation
In a group the identity is unique: if there were two, e and f, then e = e ∗ f = f. It exists regardless of whether the group is finite.
Review the concept: Identity element
An element \(e\in G\) is an identity, or neutral element, if it leaves every element of the group unchanged when operating with it.
\[e\ast a=a\ast e=a \quad \forall a\in G\]
More practice problems: identity element
- ZW-IDENTITY-ELEMENT-001 What is the neutral element of (ℤ, +)?
- ZW-IDENTITY-ELEMENT-003 The property of the neutral element e is expressed as...
- ZW-IDENTITY-ELEMENT-004 What is the neutral element of (ℚ∖{0}, ·)?
- ZW-IDENTITY-ELEMENT-005 If e and f are identities of the same group, then...
- ZW-IDENTITY-ELEMENT-006 The identity of a group is...
- ZW-IDENTITY-ELEMENT-007 In (ℤ,+), the identity element is...
- ZW-IDENTITY-ELEMENT-008 If e is the identity, what happens with a∗e?
- ZW-IDENTITY-ELEMENT-009 Which expression describes an identity e?