Series of powers of x with a logarithm as the sum
This type of question, asked 2 times: 2021 Paper 20, 2021 Paper 21. All 2 questions below, oldest first.
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Question 1
2021 Paper 20
61If 0<x<1, then 23x2+35x3+47x4+….. , is equal to :
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Question 2
2021 Paper 21
78If 0<x<1 and y=21x2+32x3+43x4+…, then the value of e1+y at x=21 is:
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