
Picklez
Registered: 04/20/08
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find a sum using sigma notation MATH HELP
#160569  12/11/08 02:23 PM (9 years, 5 months ago) 


alright, I need some math help if there is anyone out there willing to throw me a bone here
30 E (5k+3) k=1
The "E" is the Sigma sign. I need to find the sum of terms 130.
I know the long method but I know there is a short way to solve this problem, any help is greatly appreciated

Picklez
Registered: 04/20/08
Posts: 17,919
Last seen: 3 years, 10 months

Re: find a sum using sigma notation MATH HELP [Re: Picklez]
#160723  12/11/08 08:45 PM (9 years, 5 months ago) 


bump, no one?

Coaster
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Re: find a sum using sigma notation MATH HELP [Re: Picklez]
#160731  12/11/08 08:56 PM (9 years, 5 months ago) 


lol no1 is gonna help u and i would if u werent such a dick 2 me such an ez problem


Ombient
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Posts: 3,499

Re: find a sum using sigma notation MATH HELP [Re: Picklez]
#160734  12/11/08 08:59 PM (9 years, 5 months ago) 


the right equations you need should all be in your book. find out if its geometric or arithmetic, I guess right? then plug into the correct equation for sum of terms.

Picklez
Registered: 04/20/08
Posts: 17,919
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Re: find a sum using sigma notation MATH HELP [Re: Ombient]
#160743  12/11/08 09:27 PM (9 years, 5 months ago) 


Quote:
Omni said: the right equations you need should all be in your book. find out if its geometric or arithmetic, I guess right? then plug into the correct equation for sum of terms.
I dont have a math book
But fine, I will spend the next hour trying to do this problem. I got nothing but time on my hands

Coaster
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Re: find a sum using sigma notation MATH HELP [Re: Picklez]
#160744  12/11/08 09:45 PM (9 years, 5 months ago) 


my hands smell like kush n pussy


Ombient
ɥɐɹq ɹǝqos
Registered: 04/20/08
Posts: 3,499

Re: find a sum using sigma notation MATH HELP [Re: Picklez]
#160750  12/11/08 10:00 PM (9 years, 5 months ago) 


its arithmetic (diff of +5)...eq's for arithmetic sequences:
eq. to find whatever term
"where a1 is the first term of the sequence, d is the common difference, n is the number of the term to find."
eq for sum of certain number of terms
"where Sn is the sum of n terms (nth partial sum), a1 is the first term, an is the nth term."

Picklez
Registered: 04/20/08
Posts: 17,919
Last seen: 3 years, 10 months

Re: find a sum using sigma notation MATH HELP [Re: Ombient]
#160752  12/11/08 10:05 PM (9 years, 5 months ago) 


Thank you, I know that first formula pretty well, but dont think I have used the 2nd one before
Thanks!

