Let \(f\colon G\to H\) be a homomorphism . The kernel is the set \(f^{-1}(1_H)\) denoted by \(\ker f\).
Remarks
- The kernel is a subgroup of \(G\).
- The kernel is normal.
Let \(f\colon G\to H\) be a homomorphism . The kernel is the set \(f^{-1}(1_H)\) denoted by \(\ker f\).