What is the solution to the Binomial Theorem problem highlighted in red?

AI Thread Summary
The discussion centers around understanding a specific aspect of the Binomial Theorem related to a highlighted portion in a document. The participants explore how the term independent of x in the product relates to the series equal to 2. It is clarified that this term is derived from a sum of products involving coefficients and powers of x. A comparison is made between coefficients from two different expressions, revealing they are not equal. Ultimately, the confusion is resolved as one participant acknowledges their understanding of the sum of terms involved.
Miike012
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I highlighted the portion in red in the paint document that I'm not understanding.

How can we see by inspection that the product is equal to the series 2?
 

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Miike012 said:
I highlighted the portion in red in the paint document that I'm not understanding.

How can we see by inspection that the product is equal to the series 2?

The term independent of x in the product is equal to the series (2); this is because the term independent of x is a sum of terms of the form kc_k x^k \times c_k/x^k = kc_k^2.
 
pasmith said:
The term independent of x in the product is equal to the series (2); this is because the term independent of x is a sum of terms of the form kc_k x^k \times c_k/x^k = kc_k^2.
The second line in the paint document is equal to n/xn(1 + (2n-1)x + (2n-1)(2n-1)/2!x2 + ...) by using the binomial theorem

If we look at the coefficient of the second term it is equal to n(2n-1).

If we compare the coeff. n(2n -1) with the coeff. of the second term of series (2) which is
2c22 = 2(n-1)(n-2)/2! = n2 - 3n + 2 they are not equal.

Hence n(2n-1) =/= n2 - 3n + 2
 

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Never mind I see that u said its the sum of the terms... I got it now
 
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Since ##px^9+q## is the factor, then ##x^9=\frac{-q}{p}## will be one of the roots. Let ##f(x)=27x^{18}+bx^9+70##, then: $$27\left(\frac{-q}{p}\right)^2+b\left(\frac{-q}{p}\right)+70=0$$ $$b=27 \frac{q}{p}+70 \frac{p}{q}$$ $$b=\frac{27q^2+70p^2}{pq}$$ From this expression, it looks like there is no greatest value of ##b## because increasing the value of ##p## and ##q## will also increase the value of ##b##. How to find the greatest value of ##b##? Thanks
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