[" 9."1,-a,a^(2),-a^(3),...n" terms (if "a!=-1)" ."],[" 10."x^(3),x^(5),x^(7),...n" terms (if "x!=+-1" )."],[" 11.Evaluate "sum_(k=1)^(11)(2+3^(k))]

Find the sum of the GP : (i) sqrt(7)+sqrt(21)+3sqrt(7)+... to n terms (ii) 1-1/3+1/3^(2)-1/3^(3)+... to n terms (iii) 1-a+a^(2)-a^(3)+... to n terms (a ne 1) (iv) x^(3)+x^(5)+x^(7)+... to terms (v) x(x+y)+x^(2)(x^(2)+y^(2))+x^(3) (x^(3)+y^(3))+... to n terms

Find the sum of the indicated number of terms of each of the following geometric progressions: a. (i) sqrt(7),sqrt(21),3sqrt(7) ,…………..n terms. (ii) 2,-1/2,1/8 , …………….n terms 12 terms (iii) 1,1/3,1/9, ………………..,n terms 5 terms b. (i) x^(3),x^(5),x^(7) .......,n terms (x!= +-1) (ii) 1,-a,a^(2),-a^(3) ........, n terms (a!= -1) (iii) x^(2)-y^(2),x-y,(x-y)/(x+y) ................ , n terms (x+y!=1) .

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

Find the sum to n terms of the G.P. x^3,x^5,x^7,…(xne+-1)

Find the 10th term of the sequence 2x,5x^(3) , 8x^(5), 11x^(7), …

Find the sum of the series 1+3x+5x^(2)+7x^(3)+...... upto n terms.

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

Lt_(x to oo) (1)/(n^(3)) sum_(k=1)^(n)[k^(2)x]=

Find the sum of the series 1+3x+5x^2+7x^3+.......... upto n terms.