Sn is the sum of the first n terms To find the sum of the terms of an arithmetic sequence, you can use the following formulae:

Question

Sn is the sum of the first n terms
To find the sum of the terms of an arithmetic sequence, you can use the
following formulae:
A. If the first and last terms are
given:

Sn=n(A1+An)÷2

where:
Sn is the sum of the first n terms
A1 is the first term
An is the last terma
B. If the last term is not given:

Sn=n[2a+ d(n-1)]÷2
where:
Sn is the sum of the first n terms
A1 is the first term
d is the common difference

Can you prove these formulae?
One way to prove thee formulae is to use mathematica induction.​

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Đan Thu 5 years 2021-08-05T05:12:53+00:00 1 Answers 21 views 0

Answers ( )

  1. nguyetanh
    0
    2021-08-05T05:14:32+00:00
    Reply

    Answer:

    what is the direction and send me a pic of it

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