A problem on divisor numbers
Favorites|Homepage
Subscriptions | sitemap
HOME > > A problem on divisor numbers

A problem on divisor numbers

[From: ] [author: ] [Date: 13-02-24] [Hit: ]
Set up a 4-by-5 augmented matrix system with these rows: [1 1 1 1 1] [ 8 4 2 1 4] [27 9 3 1 10] [64 16 4 1 20] and use the matrix solving ability of a graphing calculator or Excel to solve.(I used OpenOffice and found the inverse matrix first, which I then multiplied by the B array.)This finds the cubic (1/6)x^3 + (1/2)x^2 + (1/3)x to model the sequence; evaluating for x = 1000 gives 167167000.......
Define p(i) as:
- 1, , when i = 1
- p(i - 1) + i * (i + 1) / 2 , when i > 1
Find p(1000)

-
Hey mate! It's not as hard as it sounds.

The first six members of the sequence are 1, 4, 10, 20, 35 and 56. (I could go on but it's not needed.) The third-order differences are the same, so it's modeled by a cubic. Set up a 4-by-5 augmented matrix system with these rows: [1 1 1 1 1] [ 8 4 2 1 4] [27 9 3 1 10] [64 16 4 1 20] and use the matrix solving ability of a graphing calculator or Excel to solve. (I used OpenOffice and found the inverse matrix first, which I then multiplied by the "B" array.) This finds the cubic (1/6)x^3 + (1/2)x^2 + (1/3)x to model the sequence; evaluating for x = 1000 gives 167167000.
1
keywords: problem,on,divisor,numbers,A problem on divisor numbers
New
Hot
© 2008-2010 http://www.science-mathematics.com . Program by zplan cms. Theme by wukong .