मराठी

Let S be the sum, P be the product and R be the sum of the reciprocals of 3 terms of a G.P. Then P2 R3 : S3 is equal to ______. - Mathematics

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प्रश्न

Let S be the sum, P be the product and R be the sum of the reciprocals of 3 terms of a G.P. Then P2 R3 : S3 is equal to ______.

पर्याय

  • 1 : 1

  • (Common ratio)n : 1

  • (First term)2 : (Common ratio)2

  • None of these

MCQ
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उत्तर

Let S be the sum, P be the product and R be the sum of the reciprocals of 3 terms of a G.P. Then P2 R3 : S3 is equal to 1 : 1.

Explanation:

Let us take a G.P. with three terms `a/r, a, ar`.

Then S = `a/r + a + ar = (a(r^2 + r + 1))/r`

P = a3

R = `r/a + 1/a + 1/ar`

= `1/a((r^2 + r + 1)/r)`

`(P^2R^3)/"S"^3 = (a^6 * 11/a^3 ((r^2 + r + 1)/r)^3)/(a^3((r^2 + r + 1)/r)^3` = 1

Therefore, the ratio is 1 : 1

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पाठ 9: Sequences and Series - Solved Examples [पृष्ठ १५९]

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एनसीईआरटी एक्झांप्लर Mathematics [English] Class 11
पाठ 9 Sequences and Series
Solved Examples | Q 18 | पृष्ठ १५९

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