MathematicsMedium178×since 2002Q5280x=∑n=0∞an,y=∑n=0∞bn,z=∑n=0∞cnx = \sum\limits_{n = 0}^\infty {{a^n},y = \sum\limits_{n = 0}^\infty {{b^n},z = \sum\limits_{n = 0}^\infty {{c^n}} } }x=n=0∑∞an,y=n=0∑∞bn,z=n=0∑∞cn, where a, b, c are in A.P. and |a| < 1, |b| < 1, |c| < 1, abc ≠\ne= 0, then :Ax, y, z are in A.P.Bx, y, z are in G.P.C1x{1 \over x}x1, 1y{1 \over y}y1, 1z{1 \over z}z1 are in A.P.D1x{1 \over x}x1 + 1y{1 \over y}y1 + 1z{1 \over z}z1 = 1 −-− (a + b + c)Check answerSkip