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Method and examples
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Arithmetic Progression |
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Problem 1 of 19 |
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1. For given arithemetic progression series ,... find th term and addition of first th terms.
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Solution
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Solution provided by AtoZmath.com
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This is demo example. Please click on Find button and solution will be displayed in Solution tab (step by step)
Arithmetic Progression |
1. For given arithemetic progression series 7,3,-1,-5,-9 ,... find 10 th term and addition of first 10 th terms.
Here first term `a = 7,`
`d = 3 - 7 = -4`
We know that, `f(n) = a + (n - 1)d`
`f(10) = 7 + (10 - 1)(-4)`
`= 7 + (-36)`
`= -29`
We know that, `S_n = n/2 [2a + (n - 1)d]`
`:. S_10 = 10/2 * [2(7) + (10 - 1)(-4)]`
`= 5 * [14 + (-36)]`
`= 5 * [-22]`
`= -110`
Hence, `10^(th)` term of the given series is `-29` and sum of first `10^(th)` term is `-110`
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