Mathematics

Mathematics

Problem

Let g(x)=∑n=1∞(−1)n−1n(x−2)ng(x)=\displaystyle \sum_{n=1}^{\infty}\frac{(-1)^{n-1}}{n}(x-2)^n, which converges for ∣x−2∣<1|x-2|<1. Which power series represents g′(x)g'(x)? a) ∑k=0∞(−1)kk+1(x−2)k\displaystyle \sum_{k=0}^{\infty} \dfrac{(-1)^{k}}{k+1}(x-2)^{k} b) ∑k=1∞(−1)k−1(x−2)k\displaystyle \sum_{k=1}^{\infty} (-1)^{k-1}(x-2)^{k} c) ∑k=0∞(−1)k(x−2)k\displaystyle \sum_{k=0}^{\infty} (-1)^{k}(x-2)^{k} d) ∑k=0∞(−1)k(k+1)(x−2)k\displaystyle \sum_{k=0}^{\infty} (-1)^{k}(k+1)(x-2)^{k}

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