BÀI 3. CHO 3 ≤ N LẺ. CHỨNG MINH RẰNG
1 ... −n n2! 1 ! !
n
n
x x⇒ ( ) ( ) ( ). ( ). ( ) ( ) ( ) ( ) ( )′ = ′ + ′ = − − + f x u x v x u x v x u x v x u x v x! !−
′ =− +=− + + + + − 2
4
1
xn
2 1 ...x x x x⇒ ( )