Let . Answer the following questions based on the coefficients in this…

MATHEMATICS · Multi-part · A Level · Mathematics · Sequences and series · Sequences and series

Problem

Let P(x)=(1−5x)12P(x)=(1-5x)^{12}. Answer the following questions based on the coefficients in this expansion. (i) Find the sum of all the coefficients of P(x)P(x). (ii) Calculate the alternating sum of the coefficients of P(x)P(x), that is, ∑k=012(−1)k{12k}(−5)k\displaystyle\sum_{k=0}^{12}(-1)^k{12\brace k}(-5)^k. (iii) Hence determine the sum of the coefficients of those terms in P(x)P(x) that contain an even power of xx. Show all steps clearly.

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