content_image/315777.jpg content_image/315779.jpg content_image/315780.jpg content_image/315778.jpg
another estimation: 

<img src='content_image/315777.jpg'>

Now we calculate the terms K$_{j}$, 1 ≤ j ≤ 6 as follows: 

<img src='content_image/315779.jpg'>

<img src='content_image/315780.jpg'>

<img src='content_image/315778.jpg'>

