ধরা যাক `a=min{x^2+2x+3 : x in R}` এবং `b=lim_(thetararr0)(1-costheta)/theta^2` তবে `overset(n)underset(r=0)(sum)a^rb^(n-r)` -এর মান হবে

Options

A. `(2^(n+1)-1)/(3*2^n)`
B. `(2^(n+1)+1)/(3*2^n)`
C. `(4^(n+1)-1)/(3*2^n)`
D. `1 / 2(2^n-1)`

Answer

C