cho dãy số vơi quy luật
$x_{1}=sin \alpha _{1}$
$ x_{2}=cos \alpha_{1}sin \alpha _{2}$
$x_{3}=cos \alpha_{1}cos \alpha _{2}sin \alpha _{3}$
...................
$x_{n}=cos \alpha _{1}cos \alpha _{2}cos \alpha _{3}.... cos \alpha_{n-1}sin \alpha _{n} $
chứng minh
$x_{1}^4+ x_{2}^4+x_{3}^4+x_{4}^4+....+x_{n}^4 \geq \dfrac{1}{n}$
1 user(s) are reading this topic
0 members, 1 guests, 0 anonymous users
