Ratio - Test : Statement & Proof : Infinite Series #Ratio - #Test #Proof : #Infinite #Series
D'Alembert's Ratio Test : Statement : Back If Σ u n is a series of positive terms such that lim (u n+1 /u n ) =l, then (a) Σ u n converges if l<1 and (b) Σ u n diverges if l>1. Proof :