# Power towers!

**Calculus**Level 5

Define \(\Large{ f }_{ n }=\underbrace{x^{ { x }^{ { . }^{ { . }^{ x } } } }}_{\text{n times}}\).

Denote \(A=\displaystyle\lim _{ x\rightarrow 1 }{ \frac { { f }_{ n }(x)-{ f }_{ n-1 }(x) }{ (1-x)^{ n } } } \), when \(n\) is even.

And denote \(B=\displaystyle\lim _{ x\rightarrow 1 }{ \frac { { f }_{ n }(x)-{ f }_{ n-1 }(x) }{ (1-x)^{ n } } } \), when \(n\) is odd.

then find \(A-B\)