The sum of n terms of the series ` (1)/(1 + x) + (2)/(1 + x^(2)) + (4)/(1 + x^(4)) + ………` is

The sum of first n terms of the series 1 + (1 + x) y+ (1 + x + x^(2)) y^(2) + (1 + x + x^(2) + x^(3))y^(3) + ……….. is

Find sum to n terms of the series 3+5X(1)/(4)+7X(1)/(4^(2))+...

Sum to n terms of the series (1)/((1+x)(1+2x))+(1)/((1+2x)(1+3x))+(1)/((1+3x)(1+4x))+ ………

Sum to n terms of the series 1+(1+x)+(1+x+x^(2))+(1+x+x^(2)+x^(3))+

Sum of n terms of the series 1+2 x+3 x^(2)+4 x^(3)+..,(x ne 1) is

Find the sum to n terms of the series , (1)/(1.2)+(1)/(2.3)+(1)/(3.4)+.... ?