Let f (x) have continuous first derivative at x = e, f '(E) = - 2 (e ^ - 1), then LIM (x → 0 +) (D / DX) f (e ^ cos √ x)=

Let f (x) have continuous first derivative at x = e, f '(E) = - 2 (e ^ - 1), then LIM (x → 0 +) (D / DX) f (e ^ cos √ x)=

（d/dx)f(e^cos√x)
=f‘(e^cos√x)*e^cos√x*sin√x*(1/2√x)
So: LIM (x → 0 +) (D / DX) f (e ^ cos √ x)
=lim(x→0+)f‘(e^cos√x)*e^cos√x*(-sin√x)*(1/2√x)
=-f‘(e)e/2
=e(e^(-1))
=1

Judgment. 1: the sum of two adjacent natural numbers must be odd
I was moved to cry

Judgment. 1: the sum of two adjacent natural numbers must be odd
Because two adjacent natural numbers must be odd and even. Sum must be odd

A natural number is a, and the two odd numbers adjacent to it are (a + 1) and (A-1)?

Wrong
A may also be odd, where a + 1 and A-1 are even