When f ∘ f = f
Difficulty: Hard · Topics: Discrete Mathematics, Functions, Function Combinatorics
f ∘ f = f bo‘lganda
Let X=\1, 2, 3, 4\. How many functions f:X→ X satisfy f° f=f?
X=\1, 2, 3, 4\ bo‘lsin. Nechta f:X→ X funksiya f° f=f ni qanoatlantiradi?