# Use of Sigma

• Jul 20th 2009, 08:18 PM
jordangiscool
Use of Sigma
I NEED HELPPPPP.....

4
E 6/j^2
j=1

i keep on getting 51/4 whats my mistake?
heres the equation i got s = 4(6+3/8) / 2

im not asking for answers...as you can see i already got the equation but i keep on getting the wrong answer
• Jul 20th 2009, 08:22 PM
mr fantastic
Quote:

Originally Posted by jordangiscool
I NEED HELPPPPP.....

4
E 6/j^2
j=1

i keep on getting 51/4 whats my mistake?
heres the equation i got s = 4(6+3/8) / 2

By definition:

$\sum_{j = 1}^{4} \frac{6}{j^2} = \frac{6}{1^2} + \frac{6}{2^2} + \frac{6}{3^2} + \frac{6}{4^2} = \, ....$
• Jul 20th 2009, 08:43 PM
songoku
that's not an arithmetic progression
• Jul 21st 2009, 06:32 AM