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hi I am learning pre-calculus 11 and am stuck on this question thank you!
Q. Determine the sum, Sn, for each arithmetic sequence described.
a) T1=7, Tn=79, n=8
they do not tell me what D is, so I am confused.. :)
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There are two formulas for the sum of an arithmetic progression.
The first formula is
= = .
It really requires to know the "d", the common difference.
But there is another formula for the sum of an arithmetic progression:
= .
for which to know , and n is enough.
So, use this second formula, and you get
= = = 344.
For arithmetic progressions, see the lessons
- Arithmetic progressions
- The proofs of the formulas for arithmetic progressions
- Problems on arithmetic progressions
- Word problems on arithmetic progressions
- Chocolate bars and arithmetic progressions
- Mathematical induction and arithmetic progressions
- One characteristic property of arithmetic progressions
- Mathematical induction for sequences other than arithmetic or geometric
- Proving inequalities by the method of Mathematical Induction
- Solved problems on arithmetic progressions
OVERVIEW of my lessons on arithmetic progressions with short annotations is in the lesson OVERVIEW of lessons on arithmetic progressions.