0 votes 0 votes Let $S=\sum_{n=0}^{\infty} n\alpha^{n}$ where $\mid \alpha \mid < 1$. The value of $\alpha$ in the range $0 < \alpha < 1$, such that $S=2 \alpha$ is _________. Signals and Systems gate2016-ee-1 fourier-transform sampling-theorem z-transform numerical-answers + – makhdoom ghaya asked Jan 29, 2017 • edited Oct 3, 2020 by go_editor makhdoom ghaya 9.4k points answer comment Share See all 0 reply Please log in or register to add a comment.