Mathematics

Mathematics

Problem

Which of the following power series equals sin⁡x\sin x for all real xx? a) ∑n=0∞(−1)nx2n(2n)!\displaystyle \sum_{n=0}^{\infty}(-1)^n\dfrac{x^{2n}}{(2n)!} b) ∑n=0∞(−1)nx2n+1(2n+1)!\displaystyle \sum_{n=0}^{\infty}(-1)^n\dfrac{x^{2n+1}}{(2n+1)!} c) ∑n=0∞(−1)nx2n+1(2n)!\displaystyle \sum_{n=0}^{\infty}(-1)^n\dfrac{x^{2n+1}}{(2n)!} d) ∑n=0∞x2n+1(2n+1)!\displaystyle \sum_{n=0}^{\infty}\dfrac{x^{2n+1}}{(2n+1)!}

Browse the problem library