हिंदी

The ratio of the coefficient of x15 to the term independent of x in x2+215x is ______.

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प्रश्न

The ratio of the coefficient of x15 to the term independent of x in `x^2 + 2^15/x` is ______.

विकल्प

  • 12:32

  • 1:32

  • 32:12

  • 32:1

MCQ
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उत्तर

The ratio of the coefficient of x15 to the term independent of x in `x^2 + 2^15/x` is 1:32.

Explanation:

Let Tr+1 be the general term of `x^2 + 2^15/x`

So, Tr+1 = `""^15"C"_r  (x^2)^(15 - r)  2^r/x`

= `""^15"C"_r (2)^r  x^(30 - 3r)`  ....(1)

Now, for the coefficient of term containing x15

30 – 3r = 15

i.e., r = 5

Therefore, 15C5 (2)5 is the coefficient of x15   ....(From (1))

To find the term independent of x

Put 30 – 3r = 0

Thus 15C10 210 is the term independent of x ....(From (1))

Now the ratio is `(""^15"C"_5  2^5)/(""^15"C"_10  2^10) = 1/2^5 = 1/32`

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अध्याय 8: Binomial Theorem - Solved Examples [पृष्ठ १४१]

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एनसीईआरटी एक्झांप्लर Mathematics Exemplar [English] Class 11
अध्याय 8 Binomial Theorem
Solved Examples | Q 21 | पृष्ठ १४१

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