Tìm tất cả các hàm $f:\mathbb{R}\rightarrow \mathbb{R}$ thoả mãn:
$f\left ( x-y+f\left ( y \right ) \right )=f\left ( x \right )+f\left ( y \right )$
Tìm tất cả các hàm $f:\mathbb{R}\rightarrow \mathbb{R}$ thoả mãn:
$f\left ( x-y+f\left ( y \right ) \right )=f\left ( x \right )+f\left ( y \right )$
0 members, 1 guests, 0 anonymous users