Help 16
∑[ 2*0.25^x, x, 0, 15] =2 2/3 =~3
Sum of the first n terms of a geometric series =
First term [ 1 - common ratio^n] / [ 1 - r]
Here.....r = (1/4) and n = 15
So we have
2 [ 1 - (1/2)^15] / [ 1 - 1/2] =
2[ 1 - (1/2)^15] / (1/2)=
4 [ 1 - (1/2) ^15] = 3.999 ≈
4
